Document ID: chunk:federal_register_of_legislation:F2021C00477:body:0:p16
Version: federal_register_of_legislation:F2021C00477
Segment Type: other
Provision Reference: 
Character Range: 42573–45490

regenerative braking system alone to be applied, provided that both the following conditions are met:
5.2.7.1. Intrinsic variations in the torque output of the electrical regenerative braking system  (e.g. as a result of changes in the electric state of charge in the traction batteries) are automatically compensated by appropriate variation in the phasing relationship as long as the requirements[5] of one of the following annexes to this Regulation are satisfied:
 Annex 3, paragraph 1.3.2., or
 Annex 6, section 5.3. (including the case with the electric motor engaged), and
 Wherever necessary, to ensure that braking rate 3/ remains related to the driver's braking demand, having regard to the available tyre/road adhesion, braking shall automatically be caused to act on all wheels of the vehicle.
5.2.8. The action of the service braking system shall be distributed between the wheels of one and the same axle symmetrically in relation to the longitudinal median plane of the vehicle.
 Compensation and functions, such as anti-lock, which may cause deviations from this symmetrical distribution shall be declared.
5.2.8.1. Compensation by the electric control transmission for deterioration or defect within the braking system shall be indicated to the driver by means of the yellow warning signal specified in paragraph 5.2.21.1.2. below. This requirement shall apply for all conditions of loading when compensation exceeds the following limits:
5.2.8.1.1. a difference in transverse braking pressures on any axle:
(a) Of 25 per cent of the higher value for vehicle decelerations  2 m/sec2,
(b) a value corresponding to 25 per cent at 2 m/sec2 for decelerations below this rate.
5.2.8.1.2. An individual compensating value on any axle:
(a)  50 per cent of the nominal value for vehicle decelerations  2 m/sec2,
(b) a value corresponding to 50 per cent of the nominal value at 2 m/sec2 for decelerations below this rate.
5.2.8.2. Compensation as defined above, is permitted only when the initial brake application is made at vehicle speeds greater than 10 km/h.
5.2.9. Malfunctions of the electric control transmission shall not apply the brakes contrary to the driver's intentions.
5.2.10. The service, secondary and parking braking systems must act on braking surfaces connected to the wheels through components of adequate strength.
 Where braking torque for a particular axle or axles is provided by both a friction braking system and an electrical regenerative braking system of category B, disconnection of the latter source is permitted, providing that the friction braking source remains permanently connected and able to provide the compensation referred to in paragraph 5.2.7.1.
 However, in the case of short disconnection transients, incomplete compensation is accepted, but within 1s, this compensation shall have attained at least 75 per cent of its final value.
 Nevertheless, in all cases,