New system tripping on low pressure??

[DTLarca]

Are you sure this unit is designed for cooling ambient air? Is it a fresh air unit? What is the design ambient temperature? I think that for your region, it could have been designed for 42°C ambient, and now it's working in ambient of 20° with a room of 20°C, so it's over cooling... and freezing over, of course.

I just noticed your post. You are probably right.

The subcool will increase as the ambient rises to design. It usually then decreases again when ambient exceeds design.

The superheat is high because the head pressure is too low but the superheat is also not so high because the evaporator air on temperature is also low. Raise the head pressure to design levels and we will see the superheat crash. This would confirm a low load condition which would be either because of low air flows or low air temperatures or both.