frost on compressor

HI,

I have a carrier primeline 69NT40-561 scroll compressor
compressor was covered with frost and pulled down temp at -15C only
supply temp and return temp sometimes equalizes
2 alarms flashes on the screen
alarm 67 and 66
anyone willing to share idea on this problem

thanks

If the compressor itself is "covered with frost" then you haven't got enough superheat, check super heat and adjust/replace TEV/EEV/metering device as neccessary.

:cool:

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I see that your areas humidity is between 45% to 80%, with a -15°C suction temperature you would expect some frosting on the cold surfaces.

Even -15 degree C suction temperature indicates that there is a chance of liquid refrfigerent being sucked in... Better check the load and refrigerent superheat, else you will end up killing the compressor.

Air flow across evaporator? No load on a system will result in low superheat and possible frosting on compressor body.

Frosting on the compressor can also be caused by over charged with refrigerant.