For trucks with air compressors (virtually all trucks with air brakes): the standard compressor air intake port located after the primary/secondary air filter assembly MUST be capped. A new dedicated air intake line with separate filter must be installed for the compressor. Failure to do this risks pressurising air accumulators with a hydrogen/air mixture — creating a serious safety hazard.
Mounting Location
The system should be mounted in a protected location with adequate ventilation. Common locations: under the tray, in the cab alcove, or in a dedicated toolbox mounting. Keep away from heat sources (exhaust, engine block) and ensure the unit is secured against vibration.
Electrical Connections
- Run 8mm B&S twin core cable from the battery to the mounting location
- Install a 40A manual reset circuit breaker in the positive line, within 300mm of the battery
- Install a constant-on 60A solenoid relay — this ensures the system only runs when the engine is on
- Connect the solenoid control wire to an ignition-switched 12V source
- Connect the PWM controller between the circuit breaker and the hydrogen system
Gas Connection
Connect the HHO gas output hose to the engine air intake — after the air filter, before the turbocharger (on turbocharged engines). Use the provided Legris HDPE push-fit fittings.
Water Supply
Fill with distilled water or resin-filtered water only. Do not use tap water without filtering. Initial electrolyte level: fill to the maximum mark. Top up as required — typically every 2–4 weeks depending on use.
PWM Setting
Set the PWM controller to produce 26–40A input current (Gen 15/20). Start at the lower end and increase gradually while monitoring water temperature. The electrolyte temperature should remain below 60°C.
Petrol Engine Guide →