Many servicemen experience service calls where the compressor has both a low head pressure and a high suction pressure. There are three main reasons why a compressor will simultaneously have a low head pressure and a high suction pressure.
Bob and Tim have arrived at the apartment house that they have been working at for the last several days. They’ve gone to the roof where the outdoor units are located. There are 60 heat pumps that use R-22 as the refrigerant. They start with Unit No. 2.
Bob and Tim are on the second day of an inspection of an apartment house building that has multiple split-system heat pumps. They have inspected all 60 outdoor units on the roof. They are now going to inspect the indoor units.
Bob and Tim have arrived at Tim’s first service call. Tim asked Bob, “What is this call all about?” Bob said, “This is a new customer that wants us to take over the maintenance work for this apartment house.”
Replacing a compressor is neither simple for a technician nor inexpensive for the customer. Before replacing a compressor, a technician needs to ensure that it is truly defective. Unfortunately, sometimes good compressors get replaced as a result of a misdiagnosed problem.
For this column I want to discuss a real life situation regarding poor cooling in a residence and reduced airflow coming from the registers in the house. The air conditioner is a three ton (36,000 btuh), HCFC-22, split type, air conditioner with the A-coil in the plenum of the furnace located in the basement.
Btu Buddy has met Bob for lunch to answer some questions that Bob had about yesterday’s service call. Bob asked, “Why did that motor have two contactors and so many wires going to it? It seemed very confusing. I am glad that I tagged those motor leads when I disconnected the motor. I never would have figured out how to reconnect the leads.”