3. ANTILOCK SYSTEM - ELECTRICAL SYSTEM.

3.1 ‘Antilock Systems’ must be powered by a 12 or 24 volt electrical supply system, through a connection to the towing vehicle, using a connector conforming to DIN Standard 72570 configured for 12 volt operation or ISO/DIN7638:1996, 1997 or 2003 configured for 12 or 24 volt operation. The voltage must be marked on the plug.

3.2 The connector must be wired to have the following functions:

3.2.1 For trailers with a 12 volt system:

Pin 1 +ve high current trailer solenoid valve supply, 20 amps minimum rated capacity 30 amps peak capacity

Pin 2 +ve low current trailer electronic unit supply, 4 amps minimum rated capacity

Pin 3 -ve low current trailer electronic unit supply, 6 amps minimum rated capacity

Pin 4 -ve high current trailer solenoid valve supply, 20 amps minimum rated capacity 30 amps peak capacity

Pin 5 trailer ‘Antilock System’ failure, switched to -ve (eg pin 3 or pin 4) upon fault detection, 2 amps minimum rated capacity

3.2.2 For trailers with a 24 volt system:

Pin 1 +ve high current trailer solenoid valve supply, 10 amps minimum rated capacity 15 amps peak capacity.

Pin 2 +ve low current trailer electronic unit supply, 2 amps minimum rated capacity

Pin 3 -ve low current trailer electronic unit supply, 3 amps minimum rated capacity

Pin 4 -ve high current trailer solenoid valve supply, 10 amps minimum rated capacity 15 amps peak capacity

Pin 5 trailer ‘Antilock System’ failure, switched to -ve (eg pin 3 or pin 4) upon fault detection, 1 amp minimum rated capacity

3.3 Any break in the supply of electricity to an ‘Antilock System’ and any electrical failure of an ‘Antilock System’ other than a failure of one or all of the electrical conductors between pins 3, 4 and 5 on the electrical connector and the antilock control module must be signalled to the towing vehicle by connecting Pin 5 on the electrical connector to -ve (ie pin 3 or pin 4).

3.4 Each ‘Antilock System’ must connect pin 5 to -ve (eg pin 3 or pin 4) when initially energised and disconnect pin 5 from -ve after not less than 2 seconds or at the latest when the trailer reaches a speed of 15 km/h and no defect is present.

3.5 Where the trailer also receives an electrical ‘Control Signal’ via an electric ‘Control Line’, the electrical connection shall conform to ISO 11992-1 and 11992-2:2003 and be a point-to-point type using the seven pin connector according to ISO 7638-1 or 7638-2:1997. The data contacts of the ISO 7368 connector shall be used to transfer information exclusively for braking (including the ‘Antilock System’) and running gear (steering, tyres and suspension) functions as specified in ISO 11992-2:2003.