SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.Copyright ©2002 Society of Automotive Engineers, Inc.
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SAE WEB ADDRESS:
SAE J2578 Issued DEC2002
4.4.14.1.14.1.1.14.1.1.24.1.1.34.1.1.44.1.24.1.34.1.3.14.1.3.24.1.44.1.54.24.2.14.2.24.2.34.2.3.14.2.3.24.2.3.34.2.3.44.2.44.2.54.2.64.2.74.2.84.34.3.14.3.24.3.34.3.3.14.3.3.24.3.44.3.54.44.4.14.4.24.4.34.4.3.14.4.3.24.4.44.4.54.4.64.4.74.4.84.4.8.14.4.8.24.4.8.34.4.8.44.4.94.4.104.4.10.14.4.10.24.4.10.3
Technical Systems Safety Guidelines....................................................................................................10General Vehicle Safety...........................................................................................................................10Design for Safety....................................................................................................................................10Failure Modes and Effects Analysis (FMEA) as Best Practice...............................................................10Isolation and Separation of Hazards.......................................................................................................10Critical Control Function.........................................................................................................................10Fail-Safe Design.....................................................................................................................................11Electromagnetic Capability (EMC) and Electrical Transients..................................................................11Fuel Cell Vehicle Crashworthiness.........................................................................................................11Fuel System Integrity..............................................................................................................................11Electrical Integrity...................................................................................................................................11Vehicle Immersion..................................................................................................................................12Towability Design Criteria.......................................................................................................................12Fuel System Safety.................................................................................................................................12Installation...............................................................................................................................................12Fail-Safe Shutoff.....................................................................................................................................12Management of Potentially Hazardous Conditions Within Vehicle Compartments.................................12Barriers...................................................................................................................................................12Potentially Flammable Atmospheres......................................................................................................13Potential Ignition Sources.......................................................................................................................13Potential Hydrogen Evolution from Traction Batteries............................................................................13Normal Discharge Systems....................................................................................................................14Discharges from Pressure Relief Devices..............................................................................................14Fueling....................................................................................................................................................14Defueling.................................................................................................................................................14Fuel System Monitoring..........................................................................................................................14Fuel Cell System Safety.........................................................................................................................14Fuel Cell System Design........................................................................................................................14Fuel Cell Stack Design...........................................................................................................................14High Voltage Isolation.............................................................................................................................15Design Validation....................................................................................................................................15Operation................................................................................................................................................15High Voltage Dielectric Withstand Capability..........................................................................................15Fuel Cell System and Stack Monitoring..................................................................................................15Electrical System Safety.........................................................................................................................15High Voltage Wire...................................................................................................................................15High Voltage Connectors........................................................................................................................15High Voltage Isolation.............................................................................................................................15Design Validation....................................................................................................................................15Operation................................................................................................................................................16High Voltage Dielectric Withstand Capability..........................................................................................16Access to Live Parts...............................................................................................................................16Labeling..................................................................................................................................................16Fusing/Overcurrent Protection................................................................................................................16Bonding and Grounding..........................................................................................................................16Vehicle Bonding......................................................................................................................................16Vehicle Interior Bonding..........................................................................................................................17Electrical Components Bonding..............................................................................................................17Grounding to Fill Station During Refueling.............................................................................................17Electrical System Fault Monitoring.........................................................................................................17Hybrid Fuel Cell Vehicles........................................................................................................................18Use of Electric Supply Equipment..........................................................................................................18Back-feed to Fuel Cell............................................................................................................................18Traction Battery Pack.............................................................................................................................18
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SAE J2578 Issued DEC2002
4.4.114.4.124.4.134.54.5.14.5.24.64.6.14.6.24.6.34.6.44.6.54.75.5.15.25.2.15.2.25.2.35.2.45.2.55.36.7.7.17.27.3Appendix AAppendix BAppendix C1.
Automatic Disconnects...........................................................................................................................18Manual Disconnects...............................................................................................................................18High Voltage Buss Discharge.................................................................................................................18Mechanical Safety..................................................................................................................................18Main Switch............................................................................................................................................18Shift Mechanisms...................................................................................................................................18Fail-Safe Procedures..............................................................................................................................19Main Switch Deactivated........................................................................................................................19Response to Crash.................................................................................................................................19Vehicle Start-Up......................................................................................................................................19Vehicle Not Moving.................................................................................................................................19Vehicle Moving.......................................................................................................................................19Safety Labeling.......................................................................................................................................19Operation................................................................................................................................................20Owner’s Guide or Manual.......................................................................................................................20Fuel Releases During Normal Operation................................................................................................20Normal Gaseous Discharges Outside Vehicle........................................................................................20Normal Gaseous Discharges to Passenger Compartment.....................................................................21Normal Gaseous Discharges to Other Compartments...........................................................................21Parking in Non-mechanically Ventilated Enclosures...............................................................................21Operation in Ventilated Structures..........................................................................................................21Byproducts..............................................................................................................................................21Emergency Response............................................................................................................................21Maintenance...........................................................................................................................................22Service Manual.......................................................................................................................................22Defueling Procedures.............................................................................................................................22Facility Safety.........................................................................................................................................22
Calculations for Fuel System Integrity Coefficients..........................................................................23Guidance for Conducting High Voltage Tests..................................................................................26Guidance for Conducting Discharge Tests.......................................................................................28
Scope—This SAE Recommended Practice identifies and defines the preferred technical guidelines relating tothe safe integration of fuel cell system, fuel storage, and electrical systems into the overall Fuel Cell Vehicle.Purpose—The purpose of this document is to provide introductory mechanical and electrical system safetyguidelines that should be considered when designing fuel cell vehicles for use on public roads.Field of Application—This document covers fuel cell vehicles designed for use on public roads.
1.1
1.2
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SAE J2578 Issued DEC2002
2.
References—The following publications form a part of this information report to the extent specified. Unlessotherwise indicated, the latest version of publications should apply.
Applicable Publications—The following publications form a part of this specification to the extent specifiedherein. Unless otherwise specified, the latest issue of SAE publications shall apply.
SAE PUBLICATIONS—Available from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001.
Applicable FMVSS standards and regulations should supersede any SAE recommended practices asdescribed in this document.
SAE J1142—Towability Design Criteria and Equipment Use—Passenger Cars, Vans, and Light-Duty
Trucks
SAE J1645—Fuel System—Electrostatic Charge
SAE J1718—Measurement of Hydrogen Gas Emission from Battery-Powered Passenger Cars and Light
Trucks during Battery Charging
SAE J1739—Potential Failure Mode and Effects Analysis in Design (Design FMEA), Potential Failure
Mode and Effects Analysis in Manufacturing and Assembly Processes (Process FMEA), and PotentialFailure Mode and Effects Analysis for Machinery (Machinery FMEA)
SAE J1742—Connections for High Voltage On-Board Road Vehicle Electrical Wiring Harnesses—Test
Methods and General Performance Requirements
SAE J1766—Recommended Practice for Electric and Hybrid Electric Vehicle Battery Systems Crash
Integrity Testing
SAE J1772—SAE Electric Vehicle Conductive Charge CouplerSAE J1773—SAE Electric Vehicle Inductively Coupling ChargingSAE J2344—Guidelines for Electric Vehicle SafetySAE J2574—Fuel Cell Vehicle Terminology
2.1
2.1.1
2.1.2
ANSI STANDARD—The following publication is provided for information purposes only and is not directlyapplicable to this document. The publication is available from ANSI, 25 West 43rd Street, New York, NY10036-8002.
ANSI Z535.4—Product Safety Sign and Label
2.1.3
FEDERAL MOTOR VEHICLE SAFETY STANDARDS (FMVSS)—The publications are available from the U.S.Government Printing Office, 710 N. Capitol St. NW, Washington, DC 20401.
The following Federal Motor Vehicle Safety Standards are specifically applicable to this document for use inthe U.S. See the Code of Federal Regulations (49 CFR 571) for other applicable FMVSS. In other countries,other regulations may apply.
FMVSS 301—Fuel system integrity
FMVSS 303—Fuel system integrity of compressed natural gas vehicles
FMVSS 305—Electric powered vehicles: electrolyte spillage and electrical shock protection
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SAE J2578 Issued DEC2002
2.1.4
IEC PUBLICATIONS—The following publications are provided for guidance. The publications are availablefrom International Electrotechnical Commission, 3, rue de Verambe, P.O. Box 131, 1211 Geneva 20Switzerland.
IEC 60079 (Parts 0 through 20)—Electrical Apparatus for Explosive Gas AtmospheresIEC 60417 (Parts 1 and 2)—Graphical Symbols for Use on Equipment
IEC 61508-1—1998 & Corrigendum: 05-1999, Functional Safety of Electrical/Electronic/Programmable
Electronic Safety-Related Systems - Part 1: General Requirements
IEC 61508-3, 1998 & Corrigendum: 04-1999—Functional Safety of Electrical/Electronic/Programmable
Electronic Safety-Related Systems - Part 3: Software Requirements
2.1.5ISO PUBLICATION—Available from ANSI, 25 West 43rd Street, New York, NY 10036-8002.
ISO 6469-2—Electric road vehicles—Safety specifications—Part 2: Functional safety means and
protection against failures
2.1.6
UL PUBLICATIONS—The following publications are provided for guidance. The publications are available fromUnderwriters Laboratories, 333 Pfingsten Road, Northbrook, IL 60062-2096.
UL 991—Standard for Tests for Safety-Related Controls Employing Solid-State DevicesUL 1998—Standard for Safety-Related Software
UL 2202—Standard for Electric Vehicle (EV) Charging System Equipment
UL 2231—Personnel Protection Systems for Electric Vehicle (EV) Supply CircuitsUL 2251—Plugs, Receptacles, and Couplers for Electric Vehicles
UL 2279—Standard for Electrical Equipment for Use in Class I, Zone 0, 1, and 2 Hazardous (Classified)
Locations
2.1.7
OTHER PUBLICATIONS—The following documents should be consulted for additional information regardingFuel Cell Vehicle safety control systems.
DGMK Research Report 508, 1996 “Avoiding the Ignition of Otto-type Fuel/Air Mixtures when Refueling
Automobiles at Gas Stations”
EPRI TR-105939—Final Report Prepared Underwriters Laboratories, December 1995, “Personnel
Protection Systems for Electric Vehicle Charging Circuits”
NFPA 496 Standard for Purged and Pressurized Enclosures for Electrical Equipment 1998 Edition
2.2
Related Publications—The following publications are provided for information purposes only and are not arequired part of this document.
SAE PUBLICATIONS—Available from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001.
SAE J551-1—Performance Levels and Methods of Measurement of Electromagnetic Compatibility of
Vehicles and Devices (60 Hz to 18 GHz)
SAE J551-2—Test Limits and Methods of Measurement of Radio Disturbance Characteristics of Vehicles,
Motorboats, and Spark-Ignited Engine-Driven Devices
SAE J551-4—Test Limits and Methods of Measurement of Radio Disturbance Characteristics of Vehicles
and Devices, Broadband and Narrowband, 150 kHz to 1000 MHz
SAE J551-5—Performance Levels and Methods of Measurement of Magnetic and Electric Field Strength
from Electric Vehicles, Broadband, 9 kHz to 30 MHz
SAE J551-11—Vehicle Electromagnetic Immunity—Off-Vehicle Source
SAE J551-12—Vehicle Electromagnetic Immunity—On-Board Transmitter SimulationSAE J551-13—Vehicle Electromagnetic Immunity—Bulk Current Injection
2.2.1
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SAE J2578 Issued DEC2002
SAE J1113-2—Electromagnetic Compatibility Measurement Procedures and Limits for Vehicle
Components (Except Aircraft)—Conducted Immunity, 30 Hz to 250 kHz—All Leads
SAE J1113-3—Conducted Immunity, 250 kHz to 5000 MHz, Direct Injection of Radio Frequency (RF)
Power
SAE J1113-4—Immunity to Radiated Electromagnetic Fields—Bulk Current Injection (BCI) MethodSAE J1113-11—Immunity to Conducted Transients on Power Leads
SAE J1113-12—Electrical Interference by Conduction and Coupling—Coupling Clamp and Chattering
Relay
SAE J1113-13—Electromagnetic Compatibility Measurement Procedure for Vehicle Components—Part
13—Immunity to Electrostatic Discharge
SAE J1113-21—Electromagnetic Compatibility Measurement Procedure for Vehicle Components—Part
21: Immunity to Electromagnetic Fields, 10 kHz to 18 GHz, Absorber-Lined Chamber
SAE J1113-24—Immunity to Radiated Electromagntic Fields; 10 kHz to 200 MHz—Crawford TEM Cell and
10 kHz to 5 GHz—Wideband TEM Cell
SAE J1113-25—Electromagnetic Compatibility Measurement Procedure for Vehicle Components—
Immunity to Radiated Electromagnetic Fields, 10 KHz to 1000 MHz—Tri-Plate Line MethodSAE J1113-26—Electromagnetic Compatibility Measurement Procedure for Vehicle Components—
Immunity to AC Power Line Electric Fields
SAE J1113-41—Limits and Methods of Measurement of Radio Disturbance Characteristics of
Components and Modules for the Protection of Receivers Used on Board Vehicles
SAE J1113-42—Electromagnetic Compatibility—Component Test Procedure—Part 42 - Conducted
Transient Emissions
SAE J1115—Guidelines for Developing and Revision SAE Nomenclature and DefinitionsSAE J1654—High Voltage Primary Cable
SAE J1673—High Voltage Automotive Wiring Assembly DesignSAE J1715—Electric Vehicle Terminology
SAE J1752-1—Electromagnetic Compatibility Measurement Procedures for Integrated Circuits—
Integrated Circuit EMC Measurement Procedures—General and Definitions
SAE J1752-2—Electromagnetic Compatibility Measurement Procedures for Integrated Circuits—
Integrated Circuit Radiated Emissions Diagnostic Procedure 1 MHz to 1000 MHz, Magnetic Field—Loop Probe
SAE J1812—Function Performance Status Classification for EMC Immunity Testing
2.2.2
ANSI STANDARDS—The following publications are provided for information purposes only and are not directlyapplicable to this document. The publications are available from ANSI, 25 West 43rd Street, New York, NY10036-8002.
ANSI/IEEE C62.41—Surge Voltages in Low-Voltage AC Power Circuits
ANSI/IEEE C62.45—Equipment Connected to Low-Voltage AC Power Circuits, Guide on Surge Testing
for
ANSI Z21.83—Standard for Stationary Fuel Cell Power Plants
2.2.3
CISPR PUBLICATIONS—The following publications are provided for information purposes only and are notdirectly applicable to this document. The publications are available from IEC. See 2.2.5.
CISPR 12—Vehicles, motorboats and spark-ignited engine-driven devices—Radio disturbance
characteristics—Limits and methods of measurement
CISPR 22—Information technology equipment—Radio disturbance characteristics—Limits and methods of
measurement
CISPR 25—Limits and methods of measurement of radio disturbance characteristics for the protection of
receivers used on board vehicles
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SAE J2578 Issued DEC2002
2.2.4
EU DIRECTIVES—The following Directive is available for download from the European Union at http://www.europa.eu.int/eur-lex/en/index.html
Commission Directive 95/54/EC—Automotive Directive (amends 72/245/EEC)
2.2.5
IEC PUBLICATIONS—The following publications are provided for guidance. The publications are availablefrom International Electrotechnical Commission, 3, rue de Verambe, P.O. Box 131, 1211 Geneva 20Switzerland.
IEC 61508-2, 2000—Functional Safety of Electrical/Electronic/Programmable Electronic Safety-Related
Systems - Part 2: Requirements for Electrical/Electronic/Programmable Electronic Safety-RelatedSystems
IEC 61508-4, 1998 & Corrigendum: 04-1999—Functional Safety of Electrical/Electronic/Programmable
Electronic Safety-Related Systems - Part 4: Definitions and Abbreviations
IEC 61508-5, 1998 & Corrigendum: 04-1999—Functional Safety of Electrical/Electronic/Programmable
Electronic Safety-Related Systems - Part 5: Examples of Methods for the Determination of SafetyIntegrity Levels
IEC 61508-6, 2000—Functional Safety of Electrical/Electronic/Programmable Electronic Safety-Related
Systems - Part 6: Guidelines on the Application of IEC 61508-2 and IEC 61508-3
IEC 61508-7, 2000—Functional Safety of Electrical/Electronic/Programmable Electronic Safety-Related
Systems - Part 7: Overview of Techniques and Measures
2.2.6ISO PUBLICATIONS—Available from ANSI, 25 West 43rd Street, New York, NY 10036-8002.
ISO 6469-1—Electric road vehicles—Safety specifications—Part 1: On-board energy storage
ISO 6469-3—Electric road vehicles—Safety specifications—Part 3: Protection of users against electrical
hazards
ISO 11451-1, 2001—Road vehicles—Vehicle test methods for electrical disturbances from narrowband
radiated electromagnetic energy—Part 1: General and definitions
ISO 11451-2, 2001—Road vehicles—Vehicle test methods for electrical disturbances from narrowband
radiated electromagnetic energy—Part 2: Off-Vehicle radiation sources
ISO 11451-3, 1994—Road vehicles—Electrical disturbances by narrowband radiated electromagnetic
energy—Vehicle test methods—Part 3: On-Board transmitter simulation
ISO 11451-4, 1995—Road vehicles—Electrical disturbances by narrowband radiated electromagnetic
energy—Vehicle test methods—Part 4: Bulk current injection (BCI)
ISO 11452-1, 2001—Road vehicles—Component test methods for electrical disturbances from
narrowband radiated electromagnetic energy—Part 1: General and definitions
ISO 11452-2, 1995—Road vehicles—Electrical disturbances by narrowband radiated electromagnetic
energy—Component test methods—Part 2: Absorber-Lined chamber
ISO 11452-3, 2001—Road vehicles—Component test methods for electrical disturbances from
narrowband radiated electromagnetic energy—Part 3: Transverse electromagnetic (TEM) cellISO 11452-4, 2001—Road vehicles—Component test methods for electrical disturbances from
narrowband radiated electromagnetic energy—Part 4: Bulk current injection (BCI)
ISO 11452-5, 1995—Road vehicles—Electrical disturbances by narrowband radiated electromagnetic
energy—Component test methods—Part 5: Stripline
ISO 11452-6, 1997 & Technical Corrigendum 1: 02-01-1999—Road vehicles—Electrical disturbances by
narrowband radiated electromagnetic energy—Component test methods—Part 6: Parallel plateantenna
ISO 11452-7, 1995—Road vehicles—Electrical disturbances by narrowband radiated electromagnetic
energy—Component test methods—Part 7: Direct radio frequency (RF) power injection
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SAE J2578 Issued DEC2002
2.2.7
OTHER PUBLICATIONS—The following documents should be consulted for additional information regardingFuel Cell Vehicle safety control systems.
FCC Rules and Regulations Parts 15 and 18.
CAN/CSA-C108.4M-1992—Limits and Methods of Measurement of Radio Interference Characteristics of
Vehicles, Motor Boats, and Spark-Ignited Engine-Driven DevicesCSA Component Acceptance Service No. 33
ICES-002—Spark Ignition Systems of Vehicles and Other Devices Equipped with Internal Combustion
Engines
MIL SPEC-1472 B for Thermal Hazards Available from the U.S. Government, DOD SSP, Subscription
Service Division, Building 4D, 700 Robbins Avenue, Philadelphia, PA 19111-5094
“Vehicle Hydrogen Storage Using Lightweight Tanks”, Lawrence Livermore Nat. Laboratory, Proceedings
of the 2000 DOE Hydrogen Program Review.
3.
Definitions—Standard Fuel Cell Vehicle (FCV) terminology is provided in SAE J2574. Terminology specific tothis document is contained in this section.
Auxiliary Circuit—Electrical circuit supplying low voltage vehicle functions other than for propulsion, such aslamps, windscreen (windshield) wiper motors, and radios.
Barrier—In the context of this document, a means for controlling leakage from spaces or compartmentspotentially containing hazardous fluids. Barriers may be passive or active.
Basic Insulation—The electrical insulation required for the proper functioning of a device, and for basicprotection against electrical shock hazard.
Class I System—An electrical system having functional (basic) insulation throughout, whose conductiveaccessible parts are connected to the protective earthing conductor and provided with an earthing terminal orconnection to the vehicle.
Class II System—An electrical system having double insulation and/or reinforced insulation throughout.Compartment—A space that is enclosed (by barriers) except for openings necessary for interconnection,control, and ventilation.
Discharges—fluids leaving a system.
Double Insulation—A system of two independent insulations, each of which is capable of acting as the soleinsulation between live and accessible parts in the event of failure of the other insulation. The insulation systemresulting from a combination of basic and supplementary insulation.
Encapsulation—The process of applying a thermoplastic or thermosetting protective or insulating coating toenclose an article by suitable means, such as brushing, dipping, spraying, thermoforming, or molding.
3.1
3.2
3.3
3.4
3.53.6
3.73.8
3.9
3.10Exhaust—discharges of spent or processed fluids.
3.11Fuel Cell Module—Fuel cell modules are comprised of one or more fuel cell stacks; connections for
conducting fuels, oxidants, and exhausts; electrical connections for the power delivered by the stacks; andmeans for monitoring and/or control. Additionally, fuel cell modules may incorporate means for conductingadditional fluids (e.g., cooling media, inert gas), means for detecting normal and/or abnormal operatingconditions, enclosures or pressure vessels, and ventilation systems.
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SAE J2578 Issued DEC2002
3.12Hazardous Area—An area or space in which an explosive gas atmosphere or other hazardous condition is or
may be expected to be present in such quantities as to require special precautions for the construction,installation and use apparatus.3.13Hazardous Condition—A condition that is potentially dangerous. Among these are hazardous fluids (3.14)
and hazardous electrical voltages (3.15).3.14Hazardous Fluids—Gases or liquids that pose potential dangers. Hazards present with fluids in fuel systems
are as follows:
a.b.
Flammability—Sufficient quantities of fuel/air mixtures at or above the lower flammability limit (LFL) areby definition dangerous. Fuel/air mixtures below 25% LFL are considered non-hazardous.
Toxicity—Point sources greater than the IDLH (Immediately Dangerous to Life and Health) andoccupiable areas greater than OSHA TWA (Time Weighted Average) should be consideredhazardous.
High Pressure—High-pressure fluids in fuel supply subsystems, fuel processors, fuel cells, and/orthermal management subsystems that can transfer kinetic energy causing personal injury.
Extreme Temperature—Very high or low temperature fluids or materials that are capable of causingpersonal injury such as burns or frostbite.
c.d.
3.15Hazardous Voltage—Intermediate or high voltage which can cause current through a human body.
Hazardous voltage levels are defined in the Outline of Investigation for Personnel Protection Systems forElectric Vehicle (EV) Supply Circuits; General Requirements, UL 2231-1 July 1996 and in UL 2202.3.16Hazardous Voltage Interlock Loop (HVIL)—The HVIL is a system intended to protect people from exposure
to hazardous voltage or other hazardous conditions. It typically detects unwanted access or faults by passing asmall (non-hazardous) signal through a loop connecting a set of normally-closed conductors, connectors,sensors, and switches to check for electrical continuity.3.17High Voltage—Voltage levels greater than 30 VAC or 60 VDC can harm humans through electric shock.3.18Ignition Sources—Thermal or electric energy sources capable of igniting flammable gas mixtures. See
4.2.3.2 for discussion of avoiding thermal, electrical, and static discharges, respectively.3.19Immediately Dangerous to Life or Health (IDLH)— An IDLH exposure condition is defined as one that
poses a threat of exposure to airborne contaminants when that exposure is likely to cause death or immediateor delayed permanent adverse health effects or prevent escape from such an environment.3.20Intermediate Voltage—Voltage levels greater than 15 VAC or 30 VDC and less than high voltage levels.3.21Normal Discharges—Discharges expected during normal operation and not associated exclusively with
failures.3.22Normal Operation—All transient and steady state operating conditions of the vehicle occurring during start,
intended operation and shut down which do not involve a component or system failure.3.23Point of Release—Interface where ventilation exhaust or other discharge potentially containing hazardous
fluids leaves the vehicle and is expelled to the surroundings, the passenger compartment, or other area that isassumed to be non-hazardous.3.24Purges—Discharges associated with the removal of fluids or types of fluids from systems.
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SAE J2578 Issued DEC2002
3.25Reinforced Insulation—A single insulation system with such mechanical and electrical qualities that it, in
itself, provides the same degree of protection against the risk of electric shock as does double insulation. Theterm “single insulation system” does not necessitate that the insulation must be in one homogeneous piece.The insulation system may comprise two or more layers that cannot be tested as supplementary or basicinsulation.3.26Releases—Discharges, which in the context of this report, are undesired or unwanted.
3.27Safety Systems—A system that monitors for potentially hazardous conditions and can initiate actions to
mitigate the situation.3.28Supplementary Insulation—An independent insulation provided in addition to the basic insulation to protect
against electric shock hazard in the event that functional insulation fails.3.29Tubing—A metallic or non-metallic enclosed conduit for transferring gaseous or liquid fluids.
3.30Vehicle Electrical Connector—A portable receptacle that by insertion into an vehicle inlet, establishes an
electrical connection to the electric vehicle for the purpose of providing power and information exchange, withmeans for attachment of flexible cord or cable. This device is a part of the coupler.3.31Vehicle Electrical Coupler—A means of enabling the connection, at will, of a flexible supply cord to the
equipment. It consists of a connector and a vehicle inlet.3.32Vents—Discharges of unspent, unprocessed, or partially processed gases or liquids.4.4.1
Technical Systems Safety Guidelines
General Vehicle Safety—It is important to protect persons from hazardous conditions, where the fundamentalhierarchy of vehicle system safety design is:
a.
To protect vehicle occupants and the public from injuries that could result from the failures ofcomponents within the vehicle systems that support operation and/or as a result of damage caused byexternal events (e.g., collisions).
To protect vehicle occupants, general public, and service personnel from hazards associated withoperation or servicing of the fuel cell vehicle (e.g., hazardous voltage, extreme temperatures, highpressure, and flammable or toxic fluids).
To minimize vehicle system damage caused by subsystem or component failures.
b.
c.
4.1.1
DESIGN FOR SAFETY—The vehicle and associated subsystems should be designed with the objective that asingle-point hardware or software failure should not result in an unreasonable safety risk to any person oruncontrolled vehicle behavior.
Failure Modes and Effects Analysis (FMEA) as Best Practice—In meeting the requirements of 4.1.1,guidance can be found in SAE J1739 Reference Manual.
Isolation and Separation of Hazards—Isolation and separation of hazards are approaches used to preventcascading of failures and preclude unwanted or unexpected interactions. Ignition sources should beisolated from hazardous fluid systems.
Critical Control Function—Safety-critical control systems should be designed such that a single hardwareor software failure will not cascade into a hazardous condition. This may include isolation, separation,redundancy, supervision, and/or other means. Guidance for hardware design can be found in IEC 61508-1and UL 991. Guidance for software design can be found in IEC 61508-3 and UL 1998.
4.1.1.1
4.1.1.2
4.1.1.3
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SAE J2578 Issued DEC2002
4.1.1.4
Fail-Safe Design—The vehicle design should consider fail-safe design of electrical and hazardous fluidsystem controls. Automatic electrical disconnects should open and fuel shutoffs should close whendeactivated. By so doing, any interruption of this control signal will cause isolation of electrical or fuelsources.
Vehicle operational safety should consider loss of vehicle power due to an automatic shutdown that may initself lead to a hazardous operating condition. A staged warning and shutdown process or some otheralternative means should be provided to mitigate the posed hazard, particularly, if the vehicle is moving.When faults that pose potential hazards are detected, specific actions to be taken are defined in 4.6.Guidance can be found in ISO 6469-2—Electric road vehicles—Safety specifications. Part 2: Functionalsafety means and protection against failures.
4.1.2
ELECTROMAGNETIC COMPATIBILITY (EMC) AND ELECTRICAL TRANSIENTS—All electrical assemblies on an FCV,which could affect safe operation of the vehicle, should be functionally tolerant of the electromagneticenvironment to which the vehicle will be exposed. This includes fluctuating voltage and load conditions,which may occur during normal operation of the vehicle during driving and fueling. Also, electrical transientsresulting from normal operation of the vehicle should not cause false shutdowns of the vehicle.
The vehicle should meet the applicable government regulatory requirements for EMC. See industrystandards and guidelines in 2.2.1, 2.2.3, 2.2.5, 2.2.6, and 2.2.7.
4.1.3
FUEL CELL VEHICLE CRASHWORTHINESS—Crashworthiness guidelines for FCVs should meet applicablegovernment regulatory requirements. In the U.S., use the applicable FMVSS (see 2.1.3). See 4.6.2 for crashresponse.
Fuel System Integrity—Refer to FMVSS 301 and FMVSS 303 for fuel system integrity requirements ofmotor vehicles using liquid fuels with boiling points below 0 °C (32 °F) and compressed natural gas,respectively. For compressed hydrogen, the following modifications to FMVSS 303 are recommendedbased on the differences in chemical and physical properties between hydrogen and natural gas. SeeAppendix A for the derivation.1a.b.
In S5.2(a)(1), change 1062 kPa (154 psi) to 5.2% of service pressure.
In S5.2(a)(2), change 895 to 2640 for 24820 kPa (3600 psig), to 2800 for 34470 kPa (5000 psig), andto 3730 for 68950 kPa (10000 psig). For other service pressures, linear interpolation between thesevalues to determine the appropriate value is allowed.
In S7.1.1 change nitrogen to helium within the on-board fuel storage system.
4.1.3.1
c.
4.1.3.2
Electrical Integrity—FMVSS 305 is recommended for FCVs with the following modification. In S5.2, S7.6.6,and S7.6.7 of FMVSS 305, an electrical isolation criterion of 125 ohms per volt may be used in place of500 ohms per volt for the fuel cell module.2 An electrical isolation of 500 ohm per volt is recommended forother high voltage propulsion circuits that contain AC or are pulsed width modulated.See also 4.6.2 and SAE J1766.
1.
Appendix A is based on the amount of fuel leakage that is equivalent in combustion energy content to the amount of gasoline leakage permit-ted by FMVSS 301 but does not address the difference in flame speed (explosion effect) between hydrogen and hydrocarbon fuels, buoyancy effects, and gases trapped in confined spaces.
2. A disconnect may be used to separate the fuel cell module from other circuits but is not effective in isolating the fuel cell module from the vehi-cle conductive structure. The 125 ohms per volt criterion for the fuel cell module is a technically practical limit that does not present a shock haz-ard in DC systems by themselves or when connected to other circuits with 500 ohms per volt isolation. See EPRI TR-105939 and IEC 479 (parts 1 and 2) for guidance.
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SAE J2578 Issued DEC2002
4.1.4
VEHICLE IMMERSION—Immersion of a FCV in water as specified by the vehicle manufacturer should not resultin electric potential or current flow, gas or liquid emissions, flame or explosion that is hazardous to anyperson inside or outside the vehicle.
TOWABILITY DESIGN CRITERIA—Specific procedures for sling, wheel-lift, or car-carrier towing should beconsidered normal service information and included in the owner’s manual/guide. Included in the proceduresshould be photographs or line drawings describing recommended attachment points. For further informationon towing, refer to SAE J1142.
Fuel System Safety—Fuel systems that store, contain, process, and/or deliver fuel should be designed tostandard engineering practices until relevant SAE documents are available. Integration of fuel systems intothe vehicle should address the following items.
INSTALLATION—Integration of hazardous fluid systems into the vehicle should address normal operatingrequirements defined in 5.2. All components and interconnecting piping and wiring should be securelymounted or supported in the vehicle to minimize damage and prevent leakage and/or malfunction.
FAIL-SAFE SHUTOFF—A means should be provided to prevent the unwanted discharge of fuel arising fromsingle-point failures to the shutoff function. The HVIL could also be used to isolate the fuel supply. See 4.1.1. MANAGEMENT OF POTENTIALLY HAZARDOUS CONDITIONS WITHIN VEHICLE COMPARTMENTS—All componentscontaining or generating hazardous fluids should be located in spaces or compartments which haveprovisions to address the following:a.b.c.
External release of hazardous fluids (as defined in 3.14) from the vehicle per 5.2.1.
The entry of hazardous fluids (as defined in 3.14) into the passenger compartment per 5.2.2.
The passage of flammable fluids (as defined in 3.14) into compartments containing equipment notsuitable for hazardous areas per 5.2.3.
4.1.5
4.2
4.2.1
4.2.2
4.2.3
Spaces or compartments should be formed using barriers defined in 4.2.3.1. Equipment installed withinthese compartments should be suitable for their environments based on control of the potentially flammableatmosphere per 4.2.3.2 and/or elimination of ignition sources per 4.2.3.3. Additional guidance can be foundin IEC 60079-10.
4.2.3.1
Barriers—Barriers may be used to form spaces or compartments with hazardous materials and separatethem from non-hazardous areas inside or surrounding the vehicle.
Barriers should control the passage of hazardous fluids by either passive or active means. All seams,gaps, and penetrations of passive barriers should be sealed sufficiently to meet 4.2.3. Active barriersshould meet the criteria for pressurization in 4.2.3.2(c).
Barriers for containing fuel-bearing equipment as well as ventilation exhaust ducts and channels should beconstructed of metallic or other materials that will not propagate flame and be designed to prevent staticelectrical discharges. Inlets and exhaust outlets should be protected such that functionality is notcompromised due to flow restrictions.
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SAE J2578 Issued DEC2002
4.2.3.2
Potentially Flammable Atmospheres—The following approaches may be used to manage potentiallyflammable atmospheres in compartments containing fuel bearing equipment by reducing the concentrationof flammable gases to below 25% LFL:a.
Ventilation—Natural or forced ventilation is an effective method for reducing the potential for theexistence of a flammable gas mixture by diluting the flammable gas to a level below its lowerflammability limit. The ventilation flow should dilute normal releases of flammable gas mixtures to lessthan 25% LFL. If the ventilation flow is incapable of diluting all releases (including abnormal releases)of flammable gas mixtures to less than 50% LFL, then safeguards should be provided per 4.2.8.
When establishing a ventilation inlet location and flow requirement, possible contamination of thediluent should be considered. Ventilation equipment and sensors within ducts and channels carryingpotentially flammable fluids should be suitable for their application. If there is a significant likelihoodthat flammable gas mixtures can exceed 25% of their lower flammability limit, this equipment shouldnot provide an ignition source per 4.2.3.3. If forced ventilation is critical to safety, a method to confirmventilation flow and shut down the fuel source as per 4.2.8 should be provided.
Encapsulation—Encapsulation may be used to isolate flammable atmospheres from potential ignitionsources within equipment. See IEC 60079-18 for guidance.
Pressurization—Pressurization is a type of protection of electrical apparatus in which safety isachieved by means of a protective gas maintained at a pressure above that of the surroundingatmosphere. The pressure differential should be at least 25 Pa (0.1 inches of water column) oropposing ventilation flow should be at least 0.33 m/s (60 fpm) to prevent the leakage of hazardousfluids through openings into non-hazardous areas. See NFPA 496 for guidance.
Consumption—Catalytic reactors or other means to reduce flammable gas concentration may be usedto reduce combustible mixtures. A means of flame suppression should be provided if catalytic reactorsor other potential ignition sources are used.
Suppressants—Inert gases or other materials may be used to reduce the effective flammability of anatmosphere or prevent combustion. The asphyxiation risk or toxicity associated with suppressantsshould be considered.
b.c.
d.
e.
4.2.3.3
Potential Ignition Sources—If a local area contains flammables exceeding 25% LFL on a frequent orcontinuous basis, then equipment installed in this area should not be an ignition source during eithernormal operation or a single failure of said equipment. If the discharge of flammables exceeds 25% LFLonly on an abnormal or infrequent basis, then equipment should not be an ignition source during normaloperation. The following ignition sources should be treated as follows:a.
External Surfaces—During normal operation, external surface temperatures of components within theareas or compartments containing fuel-bearing equipment should be less than the autoignitiontemperature of the flammable fluid. See IEC 60079-20 for guidance regarding auto ignitiontemperatures of flammable fluids.
Electrical Equipment—Electrical equipment installed within areas or compartments containing fuel-bearing equipment should be suitable for use within that area. Guidance for the determining theprotection techniques can be found in IEC 60079-14 and UL 2279.
Static Discharge—The potential for static discharge in areas or compartments containing fuel-bearingequipment should be eliminated by proper bonding and grounding. See 4.4.8 for installation ofequipment within areas containing fuel-bearing components.
Catalytic Materials—Equipment containing materials that are capable of catalyzing the reaction offlammable fluids with air should suppress the propagation of the reaction from the equipment to thesurrounding flammable atmosphere.
b.
c.
d.
4.2.3.4
Potential Hydrogen Evolution from Traction Batteries—The vehicle design should preclude the release ofhazardous gases beyond the limits defined in 4.2.3 and follow safety measures defined in 4.2.3.1, 4.2.3.2,and 4.2.3.3.
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SAE J2578 Issued DEC2002
4.2.4
NORMAL DISCHARGE SYSTEMS—The vehicle design for all fuel system exhausts, purges, vents, and othernormal discharges should meet the physical and functional requirements set forth in 4.2.3 and 5.2.
DISCHARGES FROM PRESSURE RELIEF DEVICES—Fuel systems may need to vent fuel if malfunctions oraccidents occur. It is often not practical to dilute these discharges to non-hazardous levels as done withnormal discharges, in 5.2.1, making essential the placement and direction of flow away from people andpotential ignition sources. Specifically, hydrogen discharges that exceed 25% LFL should be located high inthe vehicle or otherwise directed to avoid exposure to humans or damage to safety-critical components onthe vehicle.
All pressure relief devices (PRD) should be vented to the outside of the vehicle. Interconnecting tubing,ducting, channels, and outlets from PRDs should be constructed of materials capable of maintaining systemintegrity during venting. Interconnecting tubing made of metallic materials with melting points above 538 °C(1000 °F) are appropriate. Outlets should be protected such that functionality is not compromised due to flowrestrictions.
4.2.6
FUELING—The fueling location on the vehicle should be designed to prevent the accumulation of flammablegases and the ingress of foreign material.
The vehicle system should contain automatic systems to ensure that the vehicle traction system is de-energized and the vehicle is ready for fueling.
4.2.7
DEFUELING—The design of the fuel system should provide a means for removing fuel from the FCV formaintenance or other special purposes. For compressed gas systems, this process includes depressurizingand purging the on-board fuel storage and fuel system. Removed fuel should be transferred to either anapproved closed system or venting system.
FUEL SYSTEM MONITORING—The following faults are associated with the fuel system that may requiremonitoring to address potentially hazardous conditions.a.
Fuel Discharge Fault—A fuel discharge fault is a discharge of fuel that results in potentially flammableatmospheres in excess of the limits specified in 4.2.3. Fault detection methods may include odorants,direct measurements such as hydrogen concentration or combustibility, or indirect measurementssuch as flow or pressure measurements within the system.
Fuel Shutoff Fault—Detection of a fault in the fuel shutoff function as defined in 4.2.2.
Process Fault—A process fault is a pressure, temperature, or other process parameter exceeding itsnormal operating condition of the component or system.
Ventilation Fault—A ventilation fault is a loss or reduction of airflow intended to manage a potentiallyhazardous environment per 4.2.3.2.
4.2.5
4.2.8
b.c.d.
Items exceeding limits for safe operation should be addressed using 4.1.1.4 for guidance and 4.6 forappropriate actions.
4.3
Fuel Cell System Safety—Fuel cell systems typically contain a gaseous-fueled electrochemical reactor (thefuel cell stack) and support subsystems, which if not monitored and controlled appropriately, can expose thevehicle occupants and/or the public to specific hazards (e.g., electrical shock, fuel leak).
FUEL CELL SYSTEM DESIGN—Standard engineering practice should be used for the design of subsystems orcomponents containing hydrogen or other fuels and hazardous fluids until relevant SAE documents areavailable, and 4.2 should be used for integrating these subsystems into the vehicle. Correspondingly,subsystems using electrical components should comply with SAE J2344 and be designed to 4.4.
FUEL CELL STACK DESIGN—Fuel cell stacks should be designed to prevent hazardous operating conditionsincluding hazardous fluid leakage, overpressure, fire, and shock hazard.
4.3.1
4.3.2
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SAE J2578 Issued DEC2002
4.3.3
HIGH VOLTAGE ISOLATION—The fuel cell module should have adequate isolation resistance between its DCbuss and other electrical circuits and the vehicle conductive structure as defined in 4.3.3.1 and 4.3.3.2.Design Validation—The electrical resistance should be greater than or equal to 125 ohms per voltthroughout a range of environmental conditions, including condensation, and should achieve a resistanceof at least 500 ohm/volt by the end of test in a non-condensing environment. The isolation resistanceshould be measured at a voltage of at least 1.5 times the nominal voltage of the power system or 500VDC, whichever is higher. See Appendix B for guidance in conducting this measurement.
Operation—The electrical isolation of the fuel cell module should be at least 125 ohm/volt during normaloperation with recommended maintenance throughout the operating life of the vehicle. See 4.3.5 formonitoring requirements.
HIGH VOLTAGE DIELECTRIC WITHSTAND CAPABILITY—For design validation, each high voltage system shoulddemonstrate adequate dielectric strength such that there is no indication of a dielectric breakdown orflashover after the application of a voltage as per 4.4.4.
FUEL CELL SYSTEM AND STACK MONITORING—The following are faults associated with the fuel cell systems orthe cell stack that may require monitoring to address potentially hazardous conditions.a.
Cell Stack or Process Fault—Out-of-limit thermal, pressure, flow, or composition conditions within cellstacks or other reactors in the fuel cell system could lead to internal or external component failures andsubsequently expose personnel to hazards.
Ground Fault—Electrical isolation below the limit defined in 4.3.3.2 represents a hazard to servicepersonnel.
Low Voltage Fault—The fuel cell stack or individual cells may experience low voltage that could lead tointernal or external component failures and subsequently expose personnel to hazards.
Overcurrent Fault—Currents greater than the rated values could lead to internal or externalcomponent failures and subsequently expose personnel to hazards.
4.3.3.1
4.3.3.2
4.3.4
4.3.5
b.c.d.
Items exceeding limits for safe operation should be addressed using 4.1.1.4 for guidance and 4.6 forappropriate actions.
4.4
Electrical System Safety—FCVs typically contain potentially hazardous levels of electrical voltage or current.The intention is either to prevent inadvertent contact with hazardous voltages or to prevent the development ofan ignition source, or damage or injury from the uncontrolled release of electrical energy. Refer to SAE J2344for guidance.
HIGH VOLTAGE WIRE—Refer to SAE J2344 for guidance on high-voltage wiring assemblies. It isrecommended that harnesses containing high voltage be visually identified with a permanent orangecovering material.
HIGH VOLTAGE CONNECTORS—Connectors for high voltage components for FCVs should comply with the testmethods and general performance requirements established in SAE J1742.
HIGH VOLTAGE ISOLATION—High and intermediate voltage electrical circuits of the completed vehicle thatwere not addressed as part of 4.3.3 should have adequate isolation resistance between it and the electricalchassis and between it and other electrical circuits as defined in 4.4.3.1 and 4.4.3.2.
Design Validation—The electrical resistance should be greater than or equal to 500 ohms per voltthroughout a range of environmental conditions, including condensation. The isolation resistance shouldbe measured at a voltage of at least 1.5 times the nominal DC or peak AC voltage of the power system or500 VDC, whichever is higher. See Appendix B for guidance in conducting this measurement.
4.4.1
4.4.2
4.4.3
4.4.3.1
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SAE J2578 Issued DEC2002
4.4.3.2
Operation—Other than the fuel cell module in 4.3.3, the electrical isolation should be designed to be atleast 500 ohms per volt during normal operation throughout the operating life of the vehicle. See 4.4.9 formonitoring requirements.
HIGH VOLTAGE DIELECTRIC WITHSTAND CAPABILITY—For design validation, each high voltage system shoulddemonstrate adequate dielectric between the electrical circuits and the vehicle conductive structure suchthat there is no indication of a dielectric breakdown or flashover after the application of the appropriatevoltage for one minute.
The voltage may be either a DC voltage or an AC voltage (with a frequency between 50 Hz and 60 Hz).When a direct-current potential is used for an AC circuit, a potential of 1.414 times the applicable rms valueof alternating-current voltage specified is to be applied.
The voltage should be applied as follows for Class I equipment (with basic insulation) where U is themaximum working voltage of the equipment:a.
2 U + 1000 VAC, but not less than 1500 V rms between all high voltage circuits and exposedconductive parts or chassis (common mode) and between each electrically independent circuit and allother exposed conductive parts (differential mode).
500 VAC between all low and intermediate voltage auxiliary circuits and exposed conductive parts orchassis.
4.4.4
b.
The voltage should be applied as follows for Class II equipment (with supplementary insulation):a.
2 U + 2250 VAC, but not less than 2750 V rms between each electrically independent circuit and allother exposed conductive parts.
The voltage should be applied as follows for Class II AC supply equipment (with double or reinforcedinsulation):a.b.
2 U + 3250 VAC, but not less than 3750 V rms between all high voltage circuits and exposedconductive parts or chassis.
2 U + 3250 VAC, but not less than 3750 V rms between power circuits and auxiliary circuits.
See Appendix B for guidance.
4.4.5
ACCESS TO LIVE PARTS—An interlock, special fasteners, or other means should be provided on any coverwhose removal provides access to live parts with hazardous voltage. If a Hazardous Voltage Interlock Loopis used for safety, such interlocks may be part of this monitoring loop. Refer to 4.2.2 and SAE J2344 foradditional information on the HVIL.
LABELING—Hazardous voltage equipment or compartments containing hazardous voltage equipment shouldbe identified using the high voltage symbol from IEC 60417 as shown in Figure 1.FUSING/OVERCURRENT PROTECTION—Refer to SAE J2344 for guidance on fusing.
BONDING AND GROUNDING—If hazardous voltages are contained within a conductive exterior case orenclosure that may be exposed to human contact as installed in the vehicle, this case should be providedwith a conductive connection to the vehicle chassis.
Vehicle Bonding—All body panels (e.g., doors, hood, fill door) and components that are a part of the fillprocess (e.g., nozzle receptacle) should have an electrical connection to the vehicle conductive structure.
4.4.6
4.4.74.4.8
4.4.8.1
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SAE J2578 Issued DEC2002
FIGURE 1—HAZARDOUS VOLTAGE SYMBOL
4.4.8.2
Vehicle Interior Bonding—Interior component materials should be selected that do not promote staticdischarges.
Electrical Components Bonding—Energy storage components (e.g., stack module, batteries) and majorpower electronics components should have their external conductive cases connected directly to thevehicle conductive structure (chassis) by a ground strap, wire, welded connection or other suitable low-resistance mechanical connections. Case ground connectors routed from other components (as noted asfollows) should be connected to this grounding means.
Other components, which are located in hazardous areas or receive hazardous voltages from sourcesoutside their conductive enclosures, should have conductive cases grounded either directly as previouslystated or indirectly through the wiring harness, which carries the voltage(s) from the external source. Theintent of this guideline is that disconnecting a wiring harness used to provide indirect case groundingshould also disconnect the source of hazardous voltages.
4.4.8.4
Grounding to Fill Station During Refueling—A means needs to be provided to have the vehicle groundplane at the same potential as the fueling station prior to fill nozzle connection. A conductive path shouldexist from the vehicle chassis to ground. The total resistance through the tires should not exceed 25megohms3 and the fuel receptacle should be bonded to the chassis. See SAE J1645 for recommendedpractices for minimizing electrostatic charges and their effects. Special interdependencies with the fillingstation should be identified and addressed in 5.1.
ELECTRICAL SYSTEM FAULT MONITORING—The following are faults associated with the electrical system thatmay require monitoring to address potentially hazardous conditions.a.b.
Ground Fault —Electric isolation below the limit defined in 4.4.3.2 represents a hazard to servicepersonnel. See also 4.4.10.1.
Overcurrent—Currents greater than the values could lead to electric component damage.
4.4.8.3
4.4.9
Items exceeding limits for safe operation should be addressed using 4.1.1.4 for guidance and 4.6 forappropriate actions.
3.
National Institute for Science and Technology, “Refuelling Automobiles with Hydrogen,” September 2000 and DGMK Research Report 508 “Avoiding the Ignition of Otto-type Fuel/Air Mixtures when Refueling Automobiles at Gas Stations,” 1996, recommend individual tire resistance not exceeding 108 ohms. Four tires in parallel yield a total resistance of 25 megohms.
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SAE J2578 Issued DEC2002
4.4.10HYBRID FUEL CELL VEHICLES—Vehicles with fuel cells and batteries and/or capacitors should meet the
following requirements.4.4.10.1Use of Electric Supply Equipment—Connections between premise wiring and the FCV including on-board
and off-board chargers should conform to UL 2251 and SAE J1772 for conductive couplings or SAE J1773for inductive couplings and be located on the vehicle in an area protected from moisture, debris, etc.Connectors complying with SAE J1742 may be used if the combination of the connector and the vehiclesystem comply with UL 2251.
A conductive connector mounted on the vehicle (inlet connector) should have safety features to preventinadvertent contact with hazardous voltages such as recessed contacts or integration with the HVIL. If theHVIL is used, the inlet should include a mating connector “cap” that completes the HVIL circuit andremains on the vehicle when the portable charger is not connected to the vehicle. This HVIL will also beincluded in the portable charger connector to complete the path while the charger is connected. This inletcap may also include drive-away protection such that the vehicle cannot be driven away with the portablecharger attached to the vehicle.
The vehicle manufacturer should provide the capability to monitor any circuits energized from premisewiring during charging, and, if the electrical isolation falls below operating limit in 4.4.3.2, the circuit shouldbe de-energized.
4.4.10.2Back-Feed to Fuel Cell—The fuel cell stack module should be protected from unintended back-feed of
power from energy sources such as the traction battery pack and/or the regenerative braking system.4.4.10.3Traction Battery Pack—If the vehicle is equipped with a traction battery pack or other high voltage
batteries, the isolation of the battery from the vehicle conductive structure should comply with SAE J1766,Appendix A.4.4.11AUTOMATIC DISCONNECTS—An automatic disconnect function, should provide a means of electrically isolating
both poles of a fuel cell stack module, a traction battery, and other high voltage sources (if equipped) fromexternal circuitry or components. This function would be activated by either the main switch per 4.5.1 or asan automatic triggering protection per 4.1.1.4 or 4.6. Refer to SAE J2344 for additional information onautomatic disconnects.4.4.12MANUAL DISCONNECTS—A means should be provided to disconnect both poles or de-energize the fuel cell
module, a traction battery, and other high voltage sources (if equipped) from external circuitry orcomponents. This function would be used for vehicle assembly, service, and maintenance operations. Referto SAE J2344 for additional information on manual disconnects.4.4.13HIGH VOLTAGE BUSS DISCHARGE— Refer to SAE J2344 for guidance on high voltage buss discharge. 4.5
Mechanical Safety—Mechanical safety functionality should be provided but need not be implementedmechanically.
MAIN SWITCH—A single main switch function should be provided so that the operator can disconnect tractionpower sources per 4.4.11, shutdown the fuel cell system, and shutoff the fuel supply. The main switch shouldbe activated by and accessible to the operator, similar to a conventional ignition switch.
SHIFT MECHANISMS—Refer to SAE J2344 for guidance on preventing unintended motion of electric vehicleswhen they are parked. This guidance is also relevant to fuel cell vehicles.
4.5.1
4.5.2
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SAE J2578 Issued DEC2002
4.6
Fail-Safe Procedures—The FCV should include the ability to perform staged warnings and/or safetyshutdowns when faults that could lead to hazardous conditions are detected. As discussed in 4.1.1.4, thesequence of actions depends on the operating state of the vehicle. The vehicle control system should becapable of isolating the fuel and electrical energy supplies whether the operator has deactivated the vehiclesystems or not. Required provisions for automatic electrical disconnect are defined in 4.4.11.
A number of alternative means may be used to achieve a staged response to faults. For example, a limitedoperating strategy such as actively reducing power output and/or running on battery power to mitigate thehazard posed by the failure or other manufacturer-specific means for recovering and/or preserving poweroutput after failure of a component or subsystem may be employed.
Specific actions are defined in 4.6.1 through 4.6.5 for when hazardous faults are detected.
4.6.1
MAIN SWITCH DEACTIVATED—Deactivation of the main switch function as defined in 4.5 should shutoff the fueland disconnect the fuel cell Stack Module, Traction Battery, or other high voltage electrical power sources.RESPONSE TO CRASH—If detected by crash sensors, the automatic fuel shutoff(s) and electrical disconnect(s)should be actuated. The electrical disconnect may also be used for assuring that the electrical isolationrequired by SAE J1766 is maintained after a crash. The fuel shutoff and electrical disconnect functions maybe manually restorable.
VEHICLE START-UP—If the vehicle is in the process of start up when a potentially hazardous fault is detected,it may be appropriate to immediately shutdown and isolate the electrical and fuel sources.
VEHICLE NOT MOVING—If the vehicle has started up but is not moving when a potentially hazardous fault isdetected, a warning should be provided to the operator. If the vehicle has not moved after a predeterminedtime then it may be appropriate to execute an automatic shutdown even if the main switch is not deactivated(per 4.5.1).
VEHICLE MOVING—If the vehicle is moving when a potentially hazardous fault is detected, a warning shouldbe immediately provided to the operator. The fail-safe design (per 4.1.1.4) may delay the shut down cycle,limit power, or follow another appropriate strategy in response to this fault. Certain faults may requireimmediate removal of high voltage or traction power and/or fuel.
If the fuel cell is the sole source of power, a shutdown should be executed after the vehicle comes to rest(per 4.6.4) or the main switch is deactivated (per 4.5.1).
4.6.2
4.6.3
4.6.4
4.6.5
4.7
Safety Labeling—Safety labels, marking, or other means of identification should be employed to warn ofpotential hazards associated with the operation and service of the vehicle. High voltage lines should beidentified per 4.4.1. Electrical equipment or compartments containing hazardous voltage should be labeled per4.4.6. If there are any hazards identified with fuel bearing components or temperature extremes, guidance forlabeling can be found in ANSI Z535.4
Additionally, a label like those provided in Figure 2 should be applied to the exterior of the vehicle to warnemergency responders of the unique fuel hazards associated with fuel cell vehicles. The symbol shouldindicate the type of fuel stored in the fuel tank. The diamond should be blue, and the lettering within thediamond should be white. “Compressed Hydrogen” should be used to indicate sources of gaseous hydrogenincluding compressed gas tanks and hydrogen generation systems, “Liquid Hydrogen” should indicateliquefied hydrogen storage systems, and “CNG” should indicate the use of compressed natural gas.
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SAE J2578 Issued DEC2002
FIGURE 2—EXTERIOR FUEL TYPE LABELS
5.5.1
Operation
Owner Guide or Manual—Due to large degree of variation possible in fuel cell vehicle systems, the vehiclemanufacturer should provide an Owners Guide or Manual that addresses the unique operating, fueling, andsafety characteristics of the vehicle. It is recommended that the following items be addressed.
a.b.c.
Procedures for safe vehicle operation, including operating environments.
Precautions related to the fluids and materials stored, used, or processed in the vehicle.
Possible safety hazards posed by vehicle or system operation and appropriate action(s) if a problem isdetected. Any restrictions or building requirements related to operation or parking in residentialgarages, commercial structures, or tunnels should be noted.Fueling procedures and safety precautions.
Precautions related to operator replacement of parts or fluids.Information for roadside emergencies.
d.e.f.
5.2
Fuel Releases During Normal Operation—The following operating requirements should be met duringnormal operation. The vehicle design should account for the effects of operating variations, component wear,and ageing effects on discharges. If any failure may result in discharges with concentrations above the limitsset forth in this section, then the design of the components or systems subject to this failure mode should besuitably improved to minimize the probability of any such failures. Additionally, any cautions should beaddressed in 5.1.
NORMAL GASEOUS DISCHARGES OUTSIDE THE VEHICLE—Fuel constituents in purges, vents, and exhausts,which occur during normal operation including startup and shutdown, should be non-hazardous. See 4.2.3.2.The vehicle discharges should result in the surroundings being less than 25% LFL and below the OSHATWA (Time Weighted Average). Guidance on conducting tests that simulate outdoor operation can be foundin Appendix C. See also 5.2.4 and 5.2.5 for indoor requirements.
Discharges should nominally be less than 50% LFL at the point of release from the vehicle and at no timeexceed the lower flammability limit or the IDLH. As part of design validation, measurements should be takenin the area of maximum concentration of the discharge stream. Data should be recorded to confirm thatthese criteria are met when the vehicle is at rest.
5.2.1
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SAE J2578 Issued DEC2002
5.2.2
NORMAL GASEOUS DISCHARGES TO THE PASSENGER COMPARTMENT—Flammable gas and toxic gas levelsinside the passenger compartment should be limited to 25% LFL and OSHA TWA (Time Weighted Average).This can be accomplished using barriers, natural or forced convection, catalytic reactors (recombiners) orother means.
NORMAL GAS DISCHARGES TO OTHER COMPARTMENTS—Fluids exceeding 25% LFL should not discharge intocompartments containing equipment not suitable for hazardous locations.
PARKING IN NON-MECHANICALLY VENTILATED ENCLOSURES—For vehicles designed to be parked in garages orenclosures without forced ventilation, a test based on SAE J1718 should be conducted in an enclosure witha natural air exchange rate not exceeding 0.18 air changes per hour. See Appendix C for guidance. The following conditions should be met:a.b.
Vehicle emissions for one startup and one shutdown cycle should not result in concentrations above25% LFL or above the OSHA TWA for toxic gases within the enclosure.
Fuel permeation, leakage, and any other discharges from a vehicle when tested in the enclosureshould not result in concentrations above 25% LFL or above OSHA TWA for toxic gases.
5.2.3
5.2.4
If any single-point failure may result in concentrations above 25% LFL or above OSHA TWA, then the designof the components or systems subject to this failure mode should be suitably improved to minimize theprobability of any such failures. Additionally, any cautions should be addressed in 5.1.
5.2.5
OPERATION IN VENTILATED STRUCTURES—For vehicles designed to be operated in ventilated structures (suchas tunnels, parking structures and garages), a test should be conducted to demonstrate that discharges arenon-hazardous. This test should be conducted in an enclosure that is ventilated to no more than 0.152 m3per minute per square meter (0.5 ft3 per minute per square foot) based on the vehicle footprint. Guidance onconducting the test is provided in Appendix C. The concentration of hazardous fluids should be maintainedbelow 25% LFL and the OSHA TWA while the vehicle idles for at least three (3) hours.
Byproducts—Discharges of product water or other substances should be non-toxic and limited such that theydo not pose a hazardous condition nor affect vehicle traction.
Emergency Response—The manufacturer of the FCV should have available information for safety personneland/or emergency responders with regard to dealing with accidents involving a FCV.The following information may be requested:
a.b.c.d.
Explanation of hazards associated with the fluids, hazardous voltage systems, and any materials orcomponents in the fuel cell system or vehicle in general.Identification of vehicle by safety labels (based on 4.7).
Procedure for verifying that automatic fuel shut-off and electrical disconnection functions haveoccurred.
Location and procedures for manual shut-off of fuels and disconnection of electrical bus, if applicable.
5.3
6.
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SAE J2578 Issued DEC2002
7.7.1
Maintenance
Service Manual—Due to large degree of variation possible in fuel cell vehicle systems, the vehiclemanufacturer should be responsible for the compilation of information related to vehicle service andmaintenance. It is recommended that the following items be addressed:
a.b.c.d.e.f.
Chemical and physical properties of hazardous materials stored or processed in the vehicle.
Possible safety hazards posed by the vehicle or its systems during maintenance and appropriateaction(s) if a fault is detected.
First aid procedures specific to the unique hazards of the vehicle.
Maintenance tools, equipment, and personal protective equipment (PPE).Methods and procedures for specific maintenance work.
Suggested and required maintenance items and their schedules.
7.2
Defueling Procedures—The vehicle manufacturer should provide procedures for removing fuel from FCVs.For compressed gas fuel systems, defueling normally requires the on-board fuel storage and/or fuel system tobe depressurized to a recommended level followed by a purge with an inert gas, which reduces theatmosphere to a non-hazardous level.
Facility Safety—Vehicle repairs should be conducted in a garage facility equipped with adequate safetymeasures and in compliance with local and state building codes. Additionally, the manufacturer of the FCVshould have information about the vehicle available for building code committees or local authorities andbusinesses at their request.
7.3
PREPARED BY THE SAE SAFETY SUBCOMMITTEE OF THESAE FUEL CELL STANDARDS TECHNICAL COMMITTEE
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SAE J2578 Issued DEC2002
APPENDIX A
CALCULATIONS FOR FUEL SYSTEM INTEGRITY COEFFICIENTS
A.1
FMVSS 303 contains the following requirement for fuel system integrity of compressed natural gas (CNG)fueled vehicles. These values are based upon the physical properties of CNG (and nitrogen as a test gas) andmeasurement errors associa ted with CNG storage systems ranging from 0 to 20685 kPa (0 to 3000 psig).These values have been adjusted in this appendix to represent the physical properties of hydrogen with heliumas a test gas, and compressed hydrogen storage systems ranging from 0 to 68950 kPa (0 to 10000 psig).FMVSS 303
S5.2 Fuel system pressure drop: barrier crash
a.
For all vehicles, the pressure drop in the high pressure portion of the fuel system, expressed inkilopascals (kPa), in any fixed or moving barrier crash from vehicle impact through the 60 minuteperiod following cessation of motion should not exceed:1.2.
1062 kPa (154 psi), or
895 (T/VFS); whichever is higher
where T is the average temperature of the test gas in degrees Kelvin, stabilized to ambient temperature beforetesting, where average temperature (T) is calculated by measuring ambient temperature at the start of the testtime and then every 15 minutes until the test time of 60 minutes is completed; the sum of the ambienttemperatures is then divided by five to yield the average temperature (T); and where VFS is the internal volumein liters of the fuel container and the fuel lines up to the first pressure regulator.
The first criteria stated in FMVSS 303 S5.2(a)(1) is based upon measurement error associated with a state-of-the-art capacitance type pressure transducer that would be required for the test. The American AutomobileManufacturers Association (AAMA) provided measurement errors of 0.11% for the pressure transducer, 0.2%for thermal zero shift associated with 5.6 °C (10 °F), 0.15% for thermal coefficient sensitivity associated with5.6 °C (10 °F) and 0.056% for conversion of analog data to digital form. For a pressure range of 0 to 20685 kPa(0 to 3000 psi), the individual measurement error was aggregated to a total measurement error of ±106.1 kPa(±15.4 psi). Since the total measurement error should not exceed 10% of the value being measured, theminimum pressure drop that can be accurately measured was determined to be 1062 kPa (154 psi) for the 0 to20685 kPa (0 to 3000 psi) system.
For compressed hydrogen, current technology for vehicle systems utilizes standard tank system pressures of24820 kPa (3600 psi) and 34470 kPa (5000 psi), with the intent to progress to 68950 kPa (10000 psi) systems.The rationale for the 0 to 20685 kPa (0 to 3000 psi) systems described above yields the following for a 0 to68950 kPa (0 to 10000 psi) compressed hydrogen system:
a.b.c.d.
Pressure transducer error (0.11%) = ±75.8 kPa (±11 psi)Thermal zero shift error (0.2%) = ±137.9 kPa (±20 psi)
Thermal coefficient sensitivity error (0.15%) = ±103.4 kPa (±15 psi)Analog to digital conversion error (0.056%) = ±38.6 kPa (±5.6 psi)
Total measurement error equals ± 355.7 kPa (± 51.6 psi) for 0 to 68950 kPa (0 to 10000 psi) system and totalmeasurement error should not exceed 10% of the value measured, resulting in a minimum pressure drop valueof ±3557 kPa (±516 psi).
The second criterion stated in FMVSS 303 S5.2(a)(2) is based on the amount of CNG leakage that isequivalent in combustion energy content to the amount of gasoline leakage permitted by FMVSS 301. Thetotal amount of combustion energy released is based upon the following for CNG.
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SAE J2578 Issued DEC2002
The fuel leakage in any fixed or moving barrier crash test should not exceed:
a.b.c.
1336 kilojoules (kJ) (1266.25 Btu), in energy content from impact until motion of the vehicle hasceased;
6680 kJ (6331.25 Btu) during the five-minute period following cessation of motion; and
1336 kJ 9 (1266.25 Btu) in any one-minute interval during the 55 minutes following the five-minuteperiod specified previously.
The resulting allowed leakage is 81496 kJ from impact through the 60-minute interval after motion has ceased.For hydrogen, the mass can be calculated using the equivalent energy (81496 kJ) and the lower heating valueof hydrogen (119863 kJ/kg or 51532 Btu/lb).
81496kJ
mH=-----------------------------=0.68kg
119863kJ --------kg
(Eq. A1)
This represents the mass of hydrogen that is equivalent in combustion energy to the CNG release allowed in
FMVSS 303 but does not address the difference in flame speed (explosion effect) between hydrogen andhydrocarbon fuels, buoyancy effects, and gases trapped in confined spaces.
For a particular storage volume, initial pressure, and average gas temperature, the allowable mass release(leakage) can be expressed as an orifice (hole) size in the fuel system. Once the orifice size is determined, thetest gas (helium) can be substituted and the constant, K, in the relationship to determine the allowablepressure drop over time, ∆P = K x (T/VFS), can be determined.
The determination of the orifice size is done through a step-wise calculation of leakage through the orifice,changing the orifice size until the maximum allowable hydrogen mass release is reached. The orifice flowequation is as follows for choked flow (for most gases, a pressure ratio greater than 2):
Ps
W=CCdA----------Ts
(Eq. A2)
where Cd is the orifice discharge coefficient, A is the orifice area, Ps and Ts are the upstream (higher) pressureand temperature, respectively. C is given by:
C=
k
-------------------------------------+1Rk------------2
(Eq. A3)
+k--------1----k–1
where k is ratio of specific heats, and R is the gas constant.The scope of FMVSS 303 is as follows:
S3. Application. This document applies to passenger cars, multipurpose passenger vehicles, trucks and busesthat have a gross vehicle weight rating (GVWR) of 10,000 pounds or less and use CNG as a motor fuel. Thisstandard also applies to school buses regardless of weight that use CNG as a motor fuel.
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SAE J2578 Issued DEC2002
It is not expected that on-board fuel storage capacity for these classes of vehicles will greatly exceed 200 liters.In addition, the changes in K at a given service pressure diminish as fuel storage capacity increases (FigureA1). Finally, there is a floor in the maximum allowable pressure drop due to measurement accuracy. Therefore,the values for a 200-liter fuel storage system will be used in this document. These values are more restrictivewhen used for smaller volume systems (i.e., yield a smaller allowable pressure drop).
FIGURE A1—CRASH PRESSURE DROP K VALUES
Between service pressure levels, the changes in K values are fairly linear; therefore three K values areprovided with an allowance for interpolation between these values if other service pressures are employed.The K values appear in Table A1.
TABLE A1—K VALUES FOR HELIUM TEST GAS CRASH TESTS
Service Pressure
kPa (psig)24820 (3600)34470 (5000)68950 (10000)
K
kPa(°K/L)264028003730
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SAE J2578 Issued DEC2002
APPENDIX B
GUIDANCE FOR CONDUCTING HIGH VOLTAGE TESTS
B.1
High Voltage Isolation Test—The high voltage isolation test should be conducted on high and intermediatevoltage systems. The test may be performed on the entire system at one time or on individual assemblies andthen calculating the overall system resistance. The test generally follows the following procedure for thepurpose of design validation:
a.b.
Any on-board energy storage device (e.g., traction battery, auxiliary battery) complying with 4.4.10.3can be disconnected for this test.
Prior to conducting the test, the fuel cell system or other equipment may be preconditioned such thatnormal operating conditions are established. The fuel cell system should be shut down and its highvoltage poles should be electrically connected for this test.
Both sides of electrical circuits not under test (such as low voltage circuits) should be connected to thevehicle conductive structure at a common point. If some electronic components connected betweenthe vehicle conductive structure and the live part cannot withstand the test voltage, they should bedisconnected from the test electrical circuit. Printed-wiring assemblies and other electronic-circuitcomponents that may be damaged by application of the test potential or that short-circuit the testpotential should be removed, disconnected, or otherwise rendered inoperative before the tests aremade. Semiconductor devices in the unit can be individually shunted before the test is made to avoiddestroying them in the case of a malfunction elsewhere in the circuits.
The equipment should be subjected to a preconditioning period of at least 8 hours at 5 °C ± 2 °C,followed by a conditioning period of 8 hours at a temperature of 23 °C ± 5 °C with a humidity of 90 +10/–5% at atmospheric pressure. Alternative preconditioning and conditioning parameters may beselected provided transition across the dew point occurs shortly after the beginning of the conditioningperiod.
A test voltage of at least 1.5 times the nominal voltage of the power system or 500 VDC, whichever ishigher, should be applied for a time long enough to obtain stable reading.
The isolation resistance should be measured at the beginning of and periodically throughout theconditioning period. The measurements should be performed using suitable instruments (e.g. MΩmeter) between the live parts of each power system and the vehicle conductive structure.
c.
d.
e.f.
If a high voltage isolation test is used as part of production testing, the use of conditioning atmospheres in itemd) may be deleted and the test time may be shortened.B.2
High Voltage Withstand Test—The high voltage withstand test should be conducted on high voltagesystems. The test may be performed on the entire system at one time or on individual assemblies. The testgenerally follows the following procedure for the purpose of design validation:
a.b.
Any on-board energy storage device (e.g., traction battery, auxiliary battery) can be disconnected forthis test.
Prior to conducting the test, the fuel cell system or other equipment may be preconditioned such thatnormal operating conditions are established. The fuel cell system should be shut down and its highvoltage poles should be electrically connected for this test.
Both sides of electrical circuits not under test (such as low voltage circuits) should be connected to thevehicle conductive structure at a common point. If some electronic components connected betweenthe vehicle conductive structure and the live part cannot withstand the test voltage, they should bedisconnected from the test electrical circuit. Printed-wiring assemblies and other electronic-circuitcomponents that may be damaged by application of the test potential or that short-circuit the testpotential should be removed, disconnected, or otherwise rendered inoperative before the tests aremade. Semiconductor devices in the unit can be individually shunted before the test is made to avoiddestroying them in the case of a malfunction elsewhere in the circuits.
c.
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SAE J2578 Issued DEC2002
d.
The test should be performed by applying a DC voltage or an AC voltage (with a frequency between50 Hz and 60 Hz), for one minute between the electrical circuits and the vehicle conductive structure.When a direct-current potential is used for an AC circuit, a test potential of 1.414 times the applicablerms value of alternating-current voltage specified is to be applied.
The dielectric withstand voltage should be applied as follows for Class I equipment (with basicinsulation) where U is the maximum working voltage of the equipment:1.
2 U + 1000 VAC, but not less than 1500 V rms between all high voltage circuits and exposedconductive parts or chassis (common mode) and between each electrically independent circuitand all other exposed conductive parts (differential mode).
500 VAC between all low and intermediate voltage auxiliary circuits and exposed conductive partsor chassis.
e.
2.f.
The dielectric withstand voltage should be applied as follows for Class II equipment (withsupplementary insulation):1.
2 U + 2250 VAC, but not less than 2750 V rms between each electrically independent circuit andall other exposed conductive parts.
g.
The dielectric withstand voltage should be applied as follows for Class II AC supply equipment (withdouble or reinforced insulation):1.2.
2 U + 3250 VAC, but not less than 3750 V rms between all high voltage circuits and exposedconductive parts or chassis.
2 U + 3250 VAC, but not less than 3750 V rms between power circuits and auxiliary circuits.
If a high voltage withstand test is used as part of production testing, the test time may be shortened.
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SAE J2578 Issued DEC2002
APPENDIX C
GUIDANCE FOR CONDUCTING DISCHARGE TEST
C.1
Parking in Non-Ventilated Enclosures—The following test is based on SAE J1718 and is envisioned formeeting 5.2.4. The intent of this requirement is to evaluate the vehicle’s discharges under the most severeconditions. This may include subjecting the vehicle to temperature extremes, filing the hydrogen storagesystem to maximum design capacity, operation of the fuel cell (if designed to operate while parked), andoperation of accessories. A startup/shutdown cycle should follow the manufacturer’s instructions, includingcompletion of all required diagnostic checks and the preparation of the vehicle for movement.
The vehicle should be placed in a standard enclosed space of 3 m X 6 m X 2.6 m. If the vehicle is larger thanthe standard enclosed space, a larger enclosure may be used, but the enclosure should not be more than 2 mlarger than the vehicle in any dimension. All test equipment and sensors, including ventilation fans, need to besuitable for a potentially hazardous area. Also, the materials used to construct the facility should not introducean ignition hazard from static electricity.
An air exchange rate not exceeding 0.18 air changes per hour should be established. The exchange rate isbased on information from the study in “Vehicle Hydrogen Storage Using Lightweight Tanks”. The hydrogenconcentration in the enclosure should be monitored for a minimum of 17 hours.
The atmosphere surrounding the vehicle should be sampled for flammability and toxicity (if applicable) awayfrom the points of release. Per SAE J1718, one of the sensors should be located at the ceiling in the center ofthe room. Additional locations should be monitored to determine that the overall space meets requirements. Asa minimum, the eight (8) corners of the enclosure should be recorded.
Local flammability and toxicity readings should not exceed the criteria in 5.2.1, and the reading of any sensorinside the enclosure should meet 5.2.4 at all times.C.2
Operation in Ventilated Structures—An enclosure as described for tests of non-ventilated enclosures maybe used, but modifications are necessary to simulate forced convection.
The forced ventilation flow should be no more than 0.152 m3 per minute per square meter (0.5 ft3 per minuteper square foot) based on the vehicle footprint. In order to perform tests under a challenging (but feasible)situation, the forced ventilation should be introduced to the enclosure in the lower one (1) meter at the front ofthe vehicle and exhausted from the lower one (1) meter at the rear of the vehicle.
Measurements should follow the guidance for tests in non-ventilated enclosures. Local flammability andtoxicity readings should not exceed the criteria in 5.2.1, and the reading of any sensor inside the enclosureshould meet 5.2.5 at all times.
Tests should be repeated with the vehicle position (or direction of ventilation flow) reversed to confirm thatdirection of flow is not significant.C.3
Simulation of Outdoor Operation—An enclosure as described for tests for ventilated enclosures may beused to create a controlled environment, but some modifications are necessary.
The enclosure should be forced ventilated such that the superficial velocity of the air flow though the 3 m X2.6m front face of the enclosure averages 0.5 meters per second (1.6 foot per second). This velocity is basedon the minimum wind in IEC 60079-10 for dispersion calculations. The forced ventilation should be added tothe enclosure in the lower one (1) meter at the front of the vehicle and removed from the upper one (1) meterat the rear of the vehicle.
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SAE J2578 Issued DEC2002
Measurements should follow the guidance for the test in non-ventilated enclosures. This test should beperformed while the vehicle idles for at least 3 hours. Local flammability and toxicity readings as well asreadings of any sensor within the enclosure should not exceed the criteria in 5.2.1 at any time.
Tests should be repeated with the vehicle position reversed to confirm that direction of flow is not significant.
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SAE J2578 Issued DEC2002
Rationale—Not applicable.
Relationship of SAE Standard to ISO Standard—Not applicable.
Application—This SAE Recommended Practice identifies and defines the preferred technical guidelines
relating to the safe integration of fuel cell system, fuel storage, and electrical systems into the overallFuel Cell Vehicle.Reference Section
SAE J551-1—Performance Levels and Methods of Measurement of Electromagnetic Compatibility of
Vehicles and Devices (60 Hz to 18 GHz)SAE J551-2—Test Limits and Methods of Measurement of Radio Disturbance Characteristics of
Vehicles, Motorboats, and Spark-Ignited Engine-Driven DevicesSAE J551-4—Test Limits and Methods of Measurement of Radio Disturbance Characteristics of
Vehicles and Devices, Broadband and Narrowband, 150 kHz to 1000 MHzSAE J551-5—Performance Levels and Methods of Measurement of Magnetic and Electric Field Strength
from Electric Vehicles, Broadband, 9 kHz to 30 MHzSAE J551-11—Vehicle Electromagnetic Immunity—Off-Vehicle Source
SAE J551-12—Vehicle Electromagnetic Immunity—On-Board Transmitter SimulationSAE J551-13—Vehicle Electromagnetic Immunity—Bulk Current Injection
SAE J1113-2—Electromagnetic Compatibility Measurement Procedures and Limits for Vehicle
Components (Except Aircraft)—Conducted Immunity, 30 Hz to 250 kHz—All LeadsSAE J1113-3—Conducted Immunity, 250 kHz to 5000 MHz, Direct Injection of Radio Frequency (RF)
PowerSAE J1113-4—Immunity to Radiated Electromagnetic Fields—Bulk Current Injection (BCI) MethodSAE J1113-11—Immunity to Conducted Transients on Power Leads
SAE J1113-12—Electrical Interference by Conduction and Coupling—Coupling Clamp and Chattering
RelaySAE J1113-13—Electromagnetic Compatibility Measurement Procedure for Vehicle Components—Part
13—Immunity to Electrostatic DischargeSAE J1113-21—Electromagnetic Compatibility Measurement Procedure for Vehicle Components—Part
21: Immunity to Electromagnetic Fields, 10 kHz to 18 GHz, Absorber-Lined ChamberSAE J1113-24—Immunity to Radiated Electromagntic Fields; 10 kHz to 200 MHz—Crawford TEM Cell
and 10 kHz to 5 GHz—Wideband TEM CellSAE J1113-25—Electromagnetic Compatibility Measurement Procedure for Vehicle Components—
Immunity to Radiated Electromagnetic Fields, 10 KHz to 1000 MHz—Tri-Plate LineMethod
SAE J2578 Issued DEC2002
SAE J1113-26—Electromagnetic Compatibility Measurement Procedure for Vehicle Components—
Immunity to AC Power Line Electric FieldsSAE J1113-41—Limits and Methods of Measurement of Radio Disturbance Characteristics of
Components and Modules for the Protection of Receivers Used on Board VehiclesSAE J1113-42—Electromagnetic Compatibility - Component Test Procedure—Part 42—Conducted
Transient EmissionsSAE J1115—Guidelines for Developing and Revision SAE Nomenclature and Definitions
SAE J1142—Towability Design Criteria and Equipment Use—Passenger Cars, Vans, and Light-Duty
TrucksSAE J1645—Fuel System—Electrostatic ChargeSAE J1654—High Voltage Primary Cable
SAE J1673—High Voltage Automotive Wiring Assembly DesignSAE J1715—Electric Vehicle Terminology
SAE J1718—Measurement of Hydrogen Gas Emission from Battery-Powered Passenger Cars and Light
Trucks during Battery ChargingSAE J1739—Potential Failure Mode and Effects Analysis in Design (Design FMEA), Potential Failure
Mode and Effects Analysis in Manufacturing and Assembly Processes (Process FMEA),and Potential Failure Mode and Effects Analysis for Machinery (Machinery FMEA)SAE J1742—Connections for High Voltage On-Board Road Vehicle Electrical Wiring Harnesses—Test
Methods and General Performance RequirementsSAE J1752-1—Electromagnetic Compatibility Measurement Procedures for Integrated Circuits—
Integrated Circuit EMC Measurement Procedures—General and DefinitionSAE J1752-2—Electromagnetic Compatibility Measurement Procedures for Integrated Circuits—
Integrated Circuit Radiated Emissions Diagnostic Procedure 1 MHz to 1000 MHz,Magnetic Field—Loop ProbeSAE J1766—Recommended Practice for Electric and Hybrid Electric Vehicle Battery Systems Crash
Integrity TestingSAE J1772—SAE Electric Vehicle Conductive Charge CouplerSAE J1773—SAE Electric Vehicle Inductively Coupling Charging
SAE J1812—Function Performance Status Classification for EMC Immunity TestingSAE J2344—Guidelines for Electric Vehicle SafetySAE J2574—Fuel Cell Vehicle Terminology
ANSI/IEEE C62.41—Surge Voltages in Low-Voltage AC Power Circuits
SAE J2578 Issued DEC2002
ANSI/IEEE C62.45—Equipment Connected to Low-Voltage AC Power Circuits, Guide on Surge Testing
forANSI Z21.83—Standard for Stationary Fuel Cell Power PlantsANSI Z535.4—Product Safety Sign and Label
CAN/CSA-C108.4M-1992—Limits and Methods of Measurement of Radio Interference Characteristics
of Vehicles, Motor Boats, and Spark-Ignited Engine-Driven DevicesCISPR 12—Vehicles, motorboats and spark-ignited engine-driven devices—Radio disturbance
characteristics—Limits and methods of measurement
CISPR 22—Information technology equipment—Radio disturbance characteristics—Limits and methods
of measurementCISPR 25—Limits and methods of measurement of radio disturbance characteristics for the protection of
receivers used on board vehiclesCommission Directive 95/54/EC—Automotive Directive (amends 72/245/EEC)CSA Component Acceptance Service No. 33
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Automobiles at Gas Stations”EPRI TR-105939—Final Report Prepared Underwriters Laboratories, December 1995, “Personnel
Protection Systems for Electric Vehicle Charging Circuits”FCC Rules and Regulations Parts 15 and 18FMVSS 301—Fuel system integrity
FMVSS 303—Fuel system integrity of compressed natural gas vehicles
FMVSS 305—Electric powered vehicles: electrolyte spillage and electrical shock protection
ICES-002—Spark Ignition Systems of Vehicles and Other Devices Equipped with Internal Combustion
EnginesIEC 60079 (Parts 0 through 20)—Electrical Apparatus for Explosive Gas AtmospheresIEC 60417 (Parts 1 and 2)—Graphical Symbols for Use on Equipment
IEC 61508-1—1998 & Corrigendum: 05-1999, Functional Safety of Electrical/Electronic/Programmable
Electronic Safety-Related Systems - Part 1: General RequirementsIEC 61508-2, 2000—Functional Safety of Electrical/Electronic/Programmable Electronic Safety-Related
Systems - Part 2: Requirements for Electrical/Electronic/Programmable ElectronicSafety-Related SystemsIEC 61508-3, 1998 & Corrigendum: 04-1999—Functional Safety of Electrical/Electronic/Programmable
Electronic Safety-Related Systems - Part 3: Software Requirements
SAE J2578 Issued DEC2002
IEC 61508-4, 1998 & Corrigendum: 04-1999—Functional Safety of Electrical/Electronic/Programmable
Electronic Safety-Related Systems - Part 4: Definitions and AbbreviationsIEC 61508-5, 1998 & Corrigendum: 04-1999—Functional Safety of Electrical/Electronic/Programmable
Electronic Safety-Related Systems - Part 5: Examples of Methods for the Determinationof Safety Integrity LevelsIEC 61508-6, 2000—Functional Safety of Electrical/Electronic/Programmable Electronic Safety-Related
Systems - Part 6: Guidelines on the Application of IEC 61508-2 and IEC 61508-3IEC 61508-7, 2000—Functional Safety of Electrical/Electronic/Programmable Electronic Safety-Related
Systems - Part 7: Overview of Techniques and MeasuresISO 6469-1—Electric road vehicles—Safety specifications—Part 1: On-board energy storageISO 6469-2—Electric road vehicles—Safety specifications—Part 2: Functional safety means and
protection against failuresISO 6469-3—Electric road vehicles—Safety specifications—Part 3: Protection of users against electrical
hazardsISO 11451-1, 2001—Road vehicles—Vehicle test methods for electrical disturbances from narrowband
radiated electromagnetic energy—Part 1: General and definitionsISO 11451-2, 2001—Road vehicles—Vehicle test methods for electrical disturbances from narrowband
radiated electromagnetic energy—Part 2: Off-Vehicle radiation sourcesISO 11451-3, 1994—Road vehicles—Electrical disturbances by narrowband radiated electromagnetic
energy—Vehicle test methods—Part 3: On-Board transmitter simulationISO 11451-4, 1995—Road vehicles—Electrical disturbances by narrowband radiated electromagnetic
energy—Vehicle test methods—Part 4: Bulk current injection (BCI)ISO 11452-1, 2001—Road vehicles—Component test methods for electrical disturbances from
narrowband radiated electromagnetic energy—Part 1: General and definitionsISO 11452-2, 1995—Road vehicles—Electrical disturbances by narrowband radiated electromagnetic
energy—Component test methods—Part 2: Absorber-Lined chamberISO 11452-3, 2001—Road vehicles—Component test methods for electrical disturbances from
narrowband radiated electromagnetic energy—Part 3: Transverse electromagnetic(TEM) cellISO 11452-4, 2001—Road vehicles—Component test methods for electrical disturbances from
narrowband radiated electromagnetic energy—Part 4: Bulk current injection (BCI)ISO 11452-5, 1995—Road vehicles—Electrical disturbances by narrowband radiated electromagnetic
energy—Component test methods—Part 5: StriplineISO 11452-6, 1997 & Technical Corrigendum 1: 02-01-1999—Road vehicles—Electrical disturbances by
narrowband radiated electromagnetic energy—Component test methods—Part 6:Parallel plate antenna
SAE J2578 Issued DEC2002
ISO 11452-7, 1995—Road vehicles—Electrical disturbances by narrowband radiated electromagnetic
energy—Component test methods—Part 7: Direct radio frequency (RF) power injectionMIL SPEC-1472 B for Thermal Hazards
NFPA 496 Standard for Purged and Pressurized Enclosures for Electrical Equipment 1998 EditionUL 991—Standard for Tests for Safety-Related Controls Employing Solid-State DevicesUL 1998—Standard for Safety-Related Software
UL 2202—Standard for Electric Vehicle (EV) Charging System EquipmentUL 2231—Personnel Protection Systems for Electric Vehicle (EV) Supply CircuitsUL 2251—Plugs, Receptacles, and Couplers for Electric Vehicles
UL 2279—Standard for Electrical Equipment for Use in Class I, Zone 0, 1, and 2 Hazardous (Classified)
Locations“Vehicle Hydrogen Storage Using Lightweight Tanks”, Lawrence Livermore Nat. Laboratory,
Proceedings of the 2000 DOE Hydrogen Program Review.
Developed by the SAE Safety Subcommittee
Sponsored by the SAE Fuel Cell Standards Technical Committee
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