Category Archives: Refrigeration

How Does Start Capacitor Help Start Motor


How Does Start Capacitor Help Start Motor – Run and Start Basics

Start Capacitor with Potential Relay

Start Capacitor with Potential Relay

How Does Start Capacitor Help Start Motor – Permanent Split Capacitor Motors or PSC Motors use run capacitors to help the motor be more efficient while running. The start capacitor gives the motor a boost on start up. The run capacitor helps the motor run more efficiently. Many types of HVAC equipment use PSC motors as blowers and pumps. So in HVAC you will have motors in most applications, including residential and commercial, that use capacitors for the motor no matter the application or purpose. These motors are a step above the shaded pole type of motor which was the original type of motor used for many applications.  A shaded pole motor could have power applied to it and not move or turn backwards from its intended direction. With the advent of PSC motors those problems went away. PSC motors will always start in the direction for which it is engineered to start with a few exceptions. Even in those few exceptions the PSC motor will fight to turn in the intended direction.


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HVAC Refrigeration and Triple Evacuation


HVAC Refrigeration and Triple EvacuationHVAC Refrigeration and Triple Evacuation

There is definitely some confusion among HVAC/R technicians about the proper methods of evacuation before introducing the refrigerant to the refrigeration circuit.  Let me be clear from the start that my methods of evacuating a refrigeration circuit are based on experience, education and an official guide produced by the US Military and their specifications and proper procedures for evacuating a refrigeration system. It is the proper procedure on any US Navy ship or support ship that a refrigeration system that has been open to the environment be triple evacuated before the refrigerant is reintroduced to the refrigeration circuit.  The purpose is to prevent future problems because of contaminants including moisture in the system.


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Replace HVAC Compressor for Air Conditioner Repair


Replace HVAC Compressor for Air Conditioner Repair Decision | HVAC Refrigeration Question

Replace HVAC Compressor for Air Conditioner Repair – Question – Richard – I am an HVAC technician and have read all of your articles on refrigeration and compressors. Great information and it has helped to hone my skills and offer better service for my customers. Thanks! I was wondering what your experience is with replacing compressors. How do you arrive at the decision to replace a compressor technically speaking of course? Do you recommend repairing the air conditioner by replacing the compressor or replacing the central air conditioner? I look forward to reading your answer. Brett


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Air Conditioner Condensing Unit Frozen | AC Repair


Air Conditioner Condensing Unit Frozen | AC Repair

Air Conditioner Condensing Unit Frozen | HVAC Troubleshooting

Old Condenser

Richard – Early last month we turned our air conditioner on and it worked fine for a few days. Then I noticed it was getting a little warm in the house so I went around and checked the Air Conditioner. Of course I checked the thermostat first and then the air filter. I went up into the attic to look at the air handler. I did not notice anything out of the ordinary that I am not used to seeing but I am not an expert. Then I went out to the the condensing unit on the back patio and I saw some ice inside the condensing unit. The compressor and the all the pipes connecting to the compressor were a block of ice and frozen solid. I turned everything off and called the HVAC contractor I am used to dealing with. They told me they would send someone out to take care of it. A few hours after making the call I got a call from the technician. He told me there probably very little he could do for me now as we would have to let the ice melt before he could properly troubleshoot the problem. We agreed for him to come the next morning to check it out. He told us to leave the air handler blower fan on but make sure the condenser was off. He told me to go to the breaker box and turn the condensing unit off and use the thermostat for Fan Only operation. We did exactly as he said.


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Delay Timers and the Air Conditioner Condenser | HVAC Control


Delay Timers and the Air Conditioner Condenser - Unit with the top off - condenser fan motorDelay Timers and the Air Conditioner Condenser – Heat Pump Condenser

Air Conditioners are big HVAC refrigerators. Air Conditioners and Heat Pumps use the HVAC refrigeration cycle to transfer heat from a place where it is not wanted (inside absorbing heat with the evaporator coil) to a place that makes no difference (outside using the condensing unit)(in the cooling cycle). The heart of any HVAC air conditioning, heat pump, or refrigeration system is the compressor which pumps the refrigerant through the HVAC air conditioning system. When the refrigerant leaves the compressor it is compressed and therefore a higher pressure than it was before it entered the compressor inside the condensing unit. This pressure remains constant (give or take under certain conditions) until it passes through the metering device where the pressure and temperature are reduced. This low pressure remains constant (again give or take under certain conditions) until it again reaches the compressor inside the condensing unit and is compressed again.


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