What Is the Correct Operating Pressure for Refrigerators Using R134A?

Although the low side pressure should be around 2 psig, at times it can fluctuate from 0 to -3 psig. If the low side pressure rises to over 10 psig, the system has too much refrigerant.

When the refrigerator's compressor first begins running, the pressure will appear higher than normal. After the compressor runs for a short time, measure the pressure to get an accurate reading. If the pressure remains high, the system is probably overcharged.