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.
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 reciprocating compressor will simultaneously have a low head pressure and a high suction pressure.
Many larger compressors in the refrigeration and air conditioning field have forced-oiling systems. These compressors are usually over 5 hp. They contain an oil pump located at the end of the compressor’s crankshaft. The crankshaft is actually connected to the oil pump and supplies power, which turns the oil pump.
Historically, the two predominant motor types have been permanent split capacitor (PSC) single-speed motors and 2.3 electronically commutated motors (ECMs) with variable-speed capability. This article looks at and compares the benefits of constant torque motor technology.
The compressor’s discharge temperature can tell the service technician what is going on inside a refrigeration or air conditioning system. The compressor’s discharge temperature is a reflection of the hottest part of a refrigeration system, and there are limits as to how hot a discharge temperature should be. This article will explore discharge temperatures and their limits.
Current starting relays are used on single-phase, fractional horsepower motors requiring low starting torque. Their main function is to assist in starting the motor. Start and run capacitors can be used in conjunction with current relays to boost both starting and running torque.
The compressor's discharge temperature is often an overlooked temperature when troubleshooting a refrigeration or A/C system. However, it's very important because it's an indication of the amount of heat absorbed in the evaporator and suction line, and any heat of compression generated by the compression process.
Soldering is a viable method of joining ACR tubing and components while servicing and installing refrigeration systems. However, not all types of solders can be used satisfactorily.
What should the amperage draw be of a compressor in which the nameplate says the RLA (rated load amperage) is 59.6, but the compressor is only pulling 45 amps? Is there a problem here? Do we need to change the compressor?
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