Hi all i have just taken over a ongoing problem site. It has 10 RSXY10GYAL r22 vrv twin compressor units. A few of the systems have L0 fault codes.

One of the systems has had a new inverter board set up. And still did not work after someone fitted previous.

I checked the wiring and all seems good.

I switched to emergency and unit runs perfect (as it bypasses inverter board and compressor).

I wired a 3 phase supply to the inverter compressor to check if it was seized.(all ran ok).

Daikin tech were no help as they said it is now a old unit.

I think the fault is the main pcb as the contactors for the inverter are not pulling in and none of the yellow lights light up. but the red light is off and the 2 green lights are flashing.

Any info on L0 fault code will be a big help . 3 systems have L0 faults so will need as much info as possible thanks robin.