15.3. The actuators must be marked with a letter " E” in red at least 80mm high, with a line thickness of at least 8mm, inside a white circle of at least 100mm diameter with a red edge with a line thickness of at least 4mm. See App. 13 Diagram 4 for an example.
15.4. Pressing the fire extinguisher button must also activate disconnection of the High Voltage Battery.
15.5. The electrical circuits for the fire extinguisher and the RESS isolation must be electrically separated by the use of a two-pole momentary-on button that is waterproof to IP67.
15.6. When using a homologated fire extinguisher system designed for an ICE it is permitted to exchange the trigger buttons for alternatives that comply with the requirements listed herein.
16. Marshal Neutral Switch
16.1. To enable a marshal to isolate the RESS from the power bus in less than 2 seconds, external switch( es) which operate the general circuit breaker must be provided, which:
16.2. For a single seater, a single switch must face upwards and be recessed into the top of the survival cell no more than 150mm from the Vehicle centre line and less than 150mm from the front of the cockpit opening and less than 70mm from the extinguisher switches defined in Art. 12.6.
16.3. For a saloon two switches must face upwards and be recessed into the windscreen scuttle on either side, no more than 150mm from the side of the Vehicle, 350mm from the door aperture and less than 70mm from the extinguisher switches defined in Art. 12.6.
16.4. Each switch must be designed such that the power circuit cannot be energized using the external switch. The method of triggering( push, pull or rotation direction) must be clearly marked.
16.5. Each switch must be marked with a red spark in white edged blue triangle with a base of at least 120mm. The angle of the triangle where the spark is pointing to, must point to the button. It must be associated with a letter " N " in blue inside a white circle at least 50mm in diameter and with a blue edge. The height of both symbols must be at least 100mm. See App. 13 Diagram 5 for an example.
16.6. It is prohibited to cover the external switches in any way whatsoever.
16.7. In a crash all energy sources of the Power Circuit must be switched off automatically and the full RESS must be isolated. The arrangements must be validated by the Failure Mode and Effects Analysis( FMEA) which must be provided to ASN 3 months prior to the Vehicle inspection. An FIA approved Accident Data Recorder may be used to initiate the shutdown.
16.8. 16.8 All switches( Driver Master, Neutral and Extinguisher) must operate at a nominal 12V.
16.9. See App. 13 Diagram 3 for an example of the functional switching diagram. The Vehicle specific version must be provided to ASN 3 months prior to the Vehicle inspection.
16.10. Safety Indicator requirements are based on the specifications laid down in Appendix J – Article 253 18.22. 16.11. All indicators must have a viewing angle of at least 120 ° and a luminous flux of at least 8 lumens.
17. HV RESS status light 17.1. All Bespoke Vehicles with a HV RESS must be fitted with a HV RESS Status indicator light, which:
a. Is a Red / Green light that indicates the safety status of the RESS. b. Must be in working order throughout the Event even if power on the Vehicle has failed. c.
Indications must be visible from any point around the car, manufacturer may install multiple devices to achieve it.
d. Remains powered for at least 15 minutes after the general circuit breaker is activated. e. Is marked with a“ HIGH VOLTAGE” symbol( see App. 13 Diagram 6). f.
Has repeater indicator light on the dashboard the replicates the states of the main light. This does not have to comply with Art. 8.5.
Motorsport UK 2025 National Competition Rules Version 11
Chapter 7 Appendix 11- Electrified Vehicles 287