Mcquay Split Inverter

[xti9]

Dear all,

I have a problem with a McQuay split unit with inverter with an approximate 20m of piping. After turning on the main power and turning it on the unit operates normally and cools well. However, it intermittently pops up a fault and turns the compressor off. The flashing LED's in the outside unit indicate 12 flashes which according to troubleshooting manual indicates an IPM protection fault.

The strangest thing is that the day after this fault happened i tried the unit again and it ran for 3 hrs without a hitch. The day after it pooped up the fault after just a few minutes.

Any ideas what to look out for?

Thanks

[xti9]

Seems to have been a contact corrosion problem with sliders between the inverter module and control board!