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.
HVAC contractors tell their customers there are many reasons for properly maintaining their furnaces, air conditioners, ductwork, and add-on equipment. A well-running system is efficient and provides greater comfort while saving on energy costs. It is a no-brainer. But an added bonus is the healthy ramifications.
The good idea of sealing up a building to make it energy efficient had some unwanted side-effects. Lack of circulation or the inability of a building to breathe compounded the high humidity problem. Fortunately, the HVAC trade has remained a leader in providing information, answers, and products to combat the humidity problem.
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.”
When a refrigeration system fails, many times the cause can easily be diagnosed. However there are occasions when the cause cannot easily be determined - either the true cause is unclear or the technician is unsure of a problem. How do you work through these jobs? One method used by some techs is to “read and record.”
Bob got a call to go to a convention center where the air conditioning system was not working. It was a 75-ton unit with one compressor. The system was many years old, but had been functioning fine, until now. After checking out the unit, an ohm check showed 0 resistance to ground.
The poor economy has been hard on commercial businesses. In some cases, HVAC contractors still have service agreements with local malls and office buildings, but often, that work is being outsourced to national maintenance organizations. HVAC contractors have partnered with these organizations. Some sing their praises while others now turn and run.
Bob has been sent on a service call where the customer is complaining about her power bill. She thinks that the heat pump may be the problem. Her power bill is much higher than last year. She explained this to Bob and he started by asking a question, “Does the auxiliary heat light come on very often on your thermostat?”
Accurately troubleshooting and repairing refrigeration systems requires technicians to use many specialty instruments. They base many of their diagnoses on what is read from these instruments. Relying on them to be consistently accurate day in and day out is a must. If these tools are inaccurate, more than likely the diagnoses will be inaccurate.
This article is part two of a two-part series on ice flake machine troubleshooting. The last article, which appeared in the Feb. 7 NEWS, examined troubleshooting low and high water levels. This article will examine water impurities and mechanical problems.