Embedded Files
EV.6 ELECTRICAL SYSTEM
EV.6.1 Covers
EV.6.1.1 Nonconductive material or covers must prevent inadvertent human contact with any Tractive System voltage.
Covers must be secure and sufficiently rigid.
Removable Bodywork is not suitable to enclose Tractive System connections.
EV.6.1.2 Contact with any Tractive System connections with a 100 mm long, 6 mm diameter insulated test probe must not be possible when the Tractive System enclosures are in place.
EV.6.1.3 Tractive System components and Accumulator Containers must be protected from moisture, rain or puddles.
A rating of IP65 is recommended
EV.6.2 Insulation
EV.6.2.1 Insulation material must:
a. Be appropriate for the expected surrounding temperatures
b. Have a minimum temperature rating of 90°C
EV.6.2.2 Insulating tape or paint may be part of the insulation, but must not be the only insulation.
EV.6.3 Wiring
EV.6.3.1 All wires and terminals and other conductors used in the Tractive System must be sized for the continuous current they will conduct
EV.6.3.2 All Tractive System wiring must:
a. Be marked with wire gauge, temperature rating and insulation voltage rating.
A serial number or a norm printed on the wire is sufficient if this serial number or norm is clearly bound to the wire characteristics for example by a data sheet.
b. Have temperature rating more than or equal to 90°C
EV.6.3.3 Tractive System wiring must be:
a. Done to professional standards with sufficient strain relief
b. Protected from loosening due to vibration
c. Protected against damage by rotating and / or moving parts
d. Located out of the way of possible snagging or damage
EV.6.3.4 Any Tractive System wiring that runs outside of electrical enclosures:
a. Must meet one of:
Enclosed in separate orange nonconductive conduit
Use an orange shielded cable.
b. Must meet one of:
Run in a fully enclosed container. Bodywork is not an enclosure.
The conduit or shielded cable is securely anchored at each end to allow it to withstand a force of 200 N without straining the cable end crimp
c. Any shielded cable must have the shield grounded.
EV.6.3.5 Wiring that is not part of the Tractive System must not use orange wiring or conduit.
EV.6.4 Connections
EV.6.4.1 All Tractive System connections must:
a. Be designed to use intentional current paths through conductors designed for electrical current
b. Not rely on steel bolts to be the primary conductor
c. Not include compressible material such as plastic in the stack-up
EV.6.4.2 If external, uninsulated heat sinks are used, they must be properly grounded to the GLV System Ground, see EV.6.7
EV.6.4.3 Bolted electrical connections in the high current path of the Tractive System must include a positive locking feature to prevent unintentional loosening
Lock washers or thread locking compounds (Loctite®) or adhesives are not acceptable.
Bolts with nylon patches are allowed for blind connections into OEM components.
EV.6.4.4 Information about the electrical connections supporting the high current path must be available at Electrical Technical Inspection
EV.6.5 Voltage Separation
EV.6.5.1 Separation of Tractive System and GLV System:
a. The entire Tractive System and GLV System must be completely galvanically separated.
b. The border between Tractive and GLV System is the galvanic isolation between both systems. Therefore, some components, such as the Motor Controller, may be part of both systems.
EV.6.5.2 There must be no connection between the Chassis of the vehicle (or any other conductive surface that might be inadvertently touched by a person), and any part of any Tractive System circuits.
EV.6.5.3 Tractive System and GLV circuits must not run through the same conduit or connector, except as allowed in EV.7.8.4
EV.6.5.4 GLV Systems other than the AIRs EV.5.4, parts of the Precharge and Discharge Circuits EV.5.6, HV DC/DC converters, the AMS EV.7.3, the IMD EV.7.6, parts of the TSAL EV.5.9.1 the Energy Meter EV.3.1 and cooling fans must not be inside the Accumulator Container.
EV.6.5.5 Where both Tractive System and GLV are included inside an enclosure, they must meet one of the two:
a. Be separated by insulating barriers (in addition to the insulation on the wire) made of moisture resistant, UL recognized or equivalent insulating materials rated for 90° C or higher (such as Nomex based electrical insulation)
b. Maintain the following spacing through air, or over a surface (similar to those defined in UL1741):
U < 100 V DC 10 mm
100 V DC < U < 200 V DC 20 mm
U > 200 V DC 30 mm
EV.6.5.6 Spacing must be clearly defined. Components and cables capable of movement must be positively restrained to maintain spacing.
EV.6.5.7 If Tractive System and GLV are on the same circuit board:
a. They must be on separate, clearly defined and clearly marked areas of the board
b. Required spacing related to the spacing between traces / board areas are as follows:
Voltage Over Surface Thru Air (cut in board) Under Conformal Coating
0-50 V DC 1.6 mm 1.6 mm 1 mm
50-150 V DC 6.4 mm 3.2 mm 2 mm
150-300 V DC 9.5 mm 6.4 mm 3 mm
300-600 V DC 12.7 mm 9.5 mm 4 mm
EV.6.5.8 Teams must be prepared to show spacing on team built equipment
For inaccessible circuitry, spare boards or appropriate photographs must be available for inspection.
EV.6.5.9 All connections to external devices such as laptops from a Tractive System component must include galvanic isolation.
EV.6.6 Overcurrent Protection
EV.6.6.1 All electrical systems (both Low Voltage and High Voltage) must have appropriate Overcurrent Protection/Fusing.
EV.6.6.2 Unless otherwise allowed in the Rules, all Overcurrent Protection devices must:
a. Be rated for the highest voltage in the systems they protect.
Overcurrent Protection devices used for DC must be rated for DC and must carry a DC rating equal to or more than the system voltage
b. Have a continuous current rating less than or equal to the continuous current rating of any electrical component that it protects
c. Have an interrupt current rating higher than the theoretical short circuit current of the system that it protects
EV.6.6.3 Each parallel element of multiple parallel battery cells, capacitors, strings of battery cells, strings of capacitors, or conductors must have individual Overcurrent Protection.
EV.6.6.4 Any conductors (wires, busbars, etc) conducting the entire pack current must meet one of:
a. Be appropriately sized for the total current that the individual Overcurrent Protection devices could transmit
b. Contain additional Overcurrent Protection to protect the conductors
EV.6.6.5 Battery packs with Low Voltage or non voltage rated fusible links for cell connections may be used when all three conditions are met:
An Overcurrent Protection device rated at less than or equal to one third the sum of the parallel fusible links and complying with EV.6.6.2.b above is connected in series.
The AMS can detect an open fusible link and will Open the Shutdown Circuit EV.7.2.2 if a fault is detected.
Fusible link current rating is specified in manufacturer’s data or suitable test data is provided.
EV.6.6.6 If conductor ampacity is reduced below the ampacity of the upstream Overcurrent Protection, the reduced conductor longer than 150 mm must have additional Overcurrent Protection.
This additional Overcurrent Protection must be:
a. 150 mm or less from the source end of the reduced conductor
b. On both positive and negative conductors in the Tractive System
c. On the positive conductor in the Grounded Low Voltage System
EV.6.6.7 Cells with internal Overcurrent Protection may be used without external Overcurrent Protection if suitably rated.
Most cell internal Overcurrent Protection devices are Low Voltage or non voltage rated and conditions of EV.6.6.5 above will apply.
EV.6.7 Grounding
EV.6.7.1 Grounding is required for:
a. Parts of the vehicle which are 100 mm or less from any Tractive System component
b. The Tractive System Firewall T.1.9
EV.6.7.2 Grounded parts of the vehicle must have a resistance to GLV System Ground less than the values specified below.
a. Electrically conductive parts 300 mOhms (measured with a current of 1 A)
Examples: parts made of steel, (anodized) aluminum, any other metal parts
b. Parts which may become electrically conductive 5 Ohm
Example: carbon fiber parts
Carbon fiber parts may need special measures such as using copper mesh or similar to keep the ground resistance below 5 Ohms.
EV.6.7.3 Electrical conductivity of any part may be tested by checking any point which is likely to be conductive.
Where no convenient conductive point is available, an area of coating may be removed.
This set of rules outlines essential requirements for the electrical system. In terms of high voltage covers, these rules mandate that nonconductive materials must securely cover Tractive System components to prevent accidental contact with high voltages, and removable bodywork cannot be used for this purpose. The covers need to be sturdy enough to endure impacts. Additionally, insulation materials must be suitable for expected temperatures with a minimum rating of 90°C, and while insulating tape or paint can be used, they should not be the only insulation method employed. All Tractive System wiring must be appropriately sized for the continuous current and marked with its gauge, temperature, and voltage ratings. The wiring should be installed with professional standards, including proper strain relief and protection against vibrations and potential damage. Any exposed wiring needs to use orange nonconductive conduit or shielded cables, with the shields grounded. Tractive System connections use dedicated electrical conductors rather than relying on bolts or compressible materials. Additionally, external heat sinks must be properly grounded, and high-current connections should feature positive locking mechanisms to prevent unintentional loosening. Furthermore, there must be complete galvanic isolation between the Tractive and GLV Systems, with no shared conduits or connectors allowed. If both systems are housed within the same enclosure, they must be separated by insulating barriers or maintain specified spacing to avoid electrical interference. All electrical systems must include fuses or circuit breakers rated for the highest voltage and current they handle. Each parallel battery component must have its own overcurrent protection, and conductors must be adequately sized and protected against overcurrent. Finally, these rules require that there be grounding of vehicle parts that are close to Tractive System components and sets specific resistance values for grounded parts. Electrically conductive components must have a low resistance to the GLV System Ground, and materials like carbon fiber may need additional grounding measures to maintain acceptable resistance levels.
For more specific information about each rule, click the buttons below to navigate to the Sub-Tabs within this section.
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