Bob and Btu Buddy were on a service call yesterday where the compressor motor was running overloaded due to internal load; the bearings were dragging or worn. Btu Buddy told Bob, “Motor overload protection and circuit protection are subjects that need to be discussed later.” They’ve gotten together today for that discussion.
While repairing refrigeration equipment, technicians sometimes come up with unique methods of solving problems. Many of these are used again and again and become known as “tricks of the trade.” When a bunch of technicians get together, they oftentimes enjoy sharing new tricks they learned or developed recently. It’s like a badge of honor.
My Feb. 7 column focused on ice flake machine troubleshooting. I will have more to say on that specific topic in my April 4 column. For this column, I want to take a look at amperage as it relates to HVACR compressors.
Emerson Climate Technologies Inc. recently acknowledged its top-performing wholesalers for outstanding sales performance in 2010. Exceptional wholesalers were presented awards in four different sales categories: Peak Performance, Summit, Signature, and Center Stage. The awards were handed out during the company’s annual National Wholesaler Conference, which was held in Tucson, Ariz.
Bob got a call from the dispatcher to go to an office building that has a 3-ton heat pump compressor that has been shutting off after startup. The fan would continue to run. The building maintenance man said that he had observed the shutting down of the compressor several times.
Nearly 55,000 people ambled through the Las Vegas Convention Center during three days of non-stop activity at the industry’s largest trade show. A typical Wednesday at the expo is usually considered a light day for foot traffic. But even on the last day of the show, attendees were drawn to the 1,800-plus exhibitors’ booths displaying the latest HVACR products.
When multiple compressors are piped together with a common
suction and discharge header - such as with the arrangement of a parallel rack
configuration - oil return to each compressor is a major concern. Typical oil
recirculation rates are dependent on three factors.
Emerson Climate Technologies marked a milestone in
December 2010 when the 150,000th Copeland Scroll digital compressor was shipped
to the marine container industry. Emerson shipped its
first scroll digital compressor for refrigerated seagoing containers in 2002,
and now builds the compressors in two facilities worldwide.
Although a capillary tube can become totally restricted, a far more common problem is when it becomes partially restricted, allowing some refrigerant to flow into the evaporator but not enough to satisfy the requirements of the system. This seemingly easy problem to diagnose is actually rather tricky at times.
Thermostatic expansion valves (TXV) are responsible for metering the proper amount of refrigerant into an evaporator coil. When they fail, they either cause the evaporator to be flooded (overfed) or starved (underfed) for refrigerant. Read more and find out how to diagnose a defective TXV.