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View Full Version : Insufficient cooling Carrier 42000 BTU R22 scroll compressor (PSI readings supplied)



bighank
12-06-2014, 12:21 AM
Have a Carrier scroll compressor R22 3 1/2 ton unit outside and a 4 ton piston coil inside at furnace. R22 charge is 7 pounds. Original coil was a thermal expansion type but was leaking R22 and was replaced with a piston type 4 ton coil about 2 years ago. Cooled fine for 2 years. Started AC intermittently 2 days ago as humidity is high and temp only in the 80s. Now noticed that air coming out of 1st floor outlets not very cold.
Pressures measured at charge ports on the compressor are 140 PSI on the high side or compressor output and 97 PSI on the low or suction side of the compressor.
High side tubing is not hot and low side tubing to the inside coil is not cold.
Coil is not very cold either as I accessed it thru the holes where a humidifier is used in the winter with the furnace.

Are these pressures OK for R22 with ambient air temperature of 88 degrees F?

What are potential causes for insufficient cooling given the data supplied above?

bighank
15-06-2014, 06:02 PM
Run capacitor was bad. Fan ran but not compressor. After replacement of capacitor head pressures were 250 PSI high and 75 PSI low. Evaporator coil now cold. Can't explain original pressures measured. System ran for 2 days before capacitor died. Appears to be cooling normally now.