On startup, it should be required to have gauges connected. This is the only way you will know if the compressor is running correctly. If the compressor is running backwards, the suction pressure will not drop, and discharge pressure will not rise to normal levels. If compressor is running in backwards, remove power and reverse any two leads to the compressor or units main wire connections. Reapply power and check pressures. If pressures do not move to normal operating levels, reconnect the compressor leads as originally conﬁ gured and use normal diagnostic procedures to check operation of system.
Don’t forget to check indoor blower motor to make sure rotation is correct. Same procedures apply.