Dear Friends,

I have problem with Carrier 30HK high discharge temperature problem as
1. High discharge temperature 90'C
2. High Side pressure 180psi
3. Low side (After TXV) tmperature 4~6'C
4. Low side pressure 60~80psi

Before above found out, there was a low pressure at cut off switch. So, I top up the refrigerant from low pressure switch port which is located near piston which is gone down to negative pressure during operation. After top up it reached to 5psi.

There was different pressure between pressure differential switch point measurement (Negative pressure) and suction pressure gauge display (5psi).