Document ID: chunk:federal_register_of_legislation:F2023L01530:body:0:p16
Version: federal_register_of_legislation:F2023L01530
Segment Type: other
Provision Reference: 
Character Range: 46271–49493

burst disc) may be used outside the hydrogen storage system. The hydrogen gas discharge from other pressure relief devices shall not be directed:
                  (i) Towards exposed electrical terminals, exposed electrical switches or other ignition sources;
              (ii) Into or towards the vehicle passenger or luggage compartments;
              (iii) Into or towards any vehicle wheel housing;
              (iv) Towards hydrogen gas containers.
         7.1.3.2. Vehicle exhaust system (Annex 5, paragraph 4. test procedure)
         At the vehicle exhaust system's point of discharge, the hydrogen concentration level shall:
              (a) Not exceed 4 per cent average by volume during any moving three-second time interval during normal operation including start-up and shut-down;
              (b) And not exceed 8 per cent at any time (Annex 5, paragraph 4. test procedure).
         7.1.4. Protection against flammable conditions: single failure conditions
         7.1.4.1. Hydrogen leakage and/or permeation from the hydrogen storage system shall not directly vent into the passenger or luggage compartments, or to any enclosed or semi-enclosed spaces within the vehicle that contains unprotected ignition sources.
         7.1.4.2. Any single failure downstream of the main hydrogen shut-off valve shall not result in accumulations in levels of hydrogen concentration in the passenger compartment according to test procedure in Annex 5, paragraph 3.2.
         7.1.4.3. If, during operation, a single failure results in a hydrogen concentration exceeding 3.0 per cent by volume in air in the enclosed or semi-enclosed spaces of the vehicle, then a warning shall be provided (paragraph 7.1.6.). If the hydrogen concentration exceeds 4.0 per cent by volume in the air in the enclosed or semi-enclosed spaces of the vehicle, the main shut-off valve shall be closed to isolate the storage system. (Annex 5, paragraph 3. test procedure).
         7.1.5. Fuel system leakage
         The hydrogen fuelling line (e.g. piping, joint, etc.) downstream of the main shut-off valve(s) to the fuel cell system or the engine shall not leak. Compliance shall be verified at NWP (Annex 5, paragraph 5. test procedure).
         7.1.6. Tell-tale signal warning to driver
         The warning shall be given by a visual signal or display text with the following properties:
              (a) Visible to the driver while in the driver's designated seating position with the driver's seat belt fastened;
              (b) Yellow in colour if the detection system malfunctions (e.g. circuit disconnection, short-circuit, sensor fault). It shall be red in compliance with section paragraph 7.1.4.3;
              (c) When illuminated, shall be visible to the driver under both daylight and night time driving conditions;
              (d) Remains illuminated when 3.0 per cent concentration or detection system malfunction exists and the ignition locking system is in the "On" ("Run") position or the propulsion system is activated.
         7.1.7. Identification of hydrogen fuelled vehicles.
         On vehicles of the categories M2/N2 and M3/N3, equipped with a compressed hydrogen system, labels shall be installed