An electric compressor from ARB is installed in the engine compartment.

The considerations which led to the installation, were the following:

  • When the vehicle is parked for several days, the air pressure system looses pressure and has to be refilled. Filling the pressure tanks with the mechanical compressor takes time, the engine has to run a few minutes to fill the empty pressure tanks. Using the electric compressor as support, it ensures that the vehicle is ready to leave quickly.
  • If the vehicle is parked in a hall / garage, letting the engine run for a few minutes produces a lot of exhaust fumes. If the pressure tanks are filled with the electric compresser, the vehicle is ready for departure as soon as the engine is started.
  • The filling of a tire can be done by the electric compressor, the motor does not have to run all the time when filling up 6 large tires.

All of these considerations proofed wrong in practical use:

  • the electric compressor is almost as loud as the current Deutz engine.
  • it takes a very long time until there is enough pressure to release the parking brake.
  • although the compressor is offered as a 24V device, it still requires 12V to operate the fan, the illuminated switch and the relay. As I use lithium iron phosphate batteries, I have no 12V available. I therefore had to rebuild the compressor to a "real" 24V compressor, ie installing a 24V relay and a 24V fan.
  • as the connection of the electric compressor was parallel to the mechanical compressor, additional back-pressure valves had to be installed.
  • the capacity of the compressor is not bad, but it is low compared to the mechanical compressor. Tyre inflation with only the electric compressor is a less-than-ideal solution.

Therefore it is better to ensure that the compressed air supply is properly sealed and there is little pressure loss even after a longer standing period.