Will a compressor run without freon?
Neighbors 2004 Forest River TT air conditioner is not cooling. Fan, blower runs fine, compressor also as it is hot to the touch. My experience has been if there is no freon the compressor will not run...
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If the compressor is hot to the touch, it has been running. They do have internal thermal overloads that will sometimes open is a compressor is locked and tries to draw too much current on start-up. When the overload cools, it repeats the cycle. I'm not sure what the interval of the cycle is on the Japanese compressors in the roof top units, but on the Tecumseh compressors it seems to be in he range of 20-25 seconds. The alternate symptom if a compressor is locked is that it will draw LRA and trip the breaker. Likewise, if there is a winding shorted to the case, it will also trip the breaker in lieu of trying to run.
There is an internal coupling that connects the motor to the vanes in a rotary compressor and that coupling can fail. When it does, the compressor motor runs and it does get hot because there is no refrigerant moving through the system to assist is cooling. It's easily diagnosed with a clamp on meter because the amp draw of the compressor will drop to about half of the normal draw. You have to be careful diagnosing one with this method because if the unit loses it's charge, the compressor amp draw will also drop, so you have to be a little bit familiar with what you are looking at or it can lead you down the path.
There is an internal coupling that connects the motor to the vanes in a rotary compressor and that coupling can fail. When it does, the compressor motor runs and it does get hot because there is no refrigerant moving through the system to assist is cooling. It's easily diagnosed with a clamp on meter because the amp draw of the compressor will drop to about half of the normal draw. You have to be careful diagnosing one with this method because if the unit loses it's charge, the compressor amp draw will also drop, so you have to be a little bit familiar with what you are looking at or it can lead you down the path.
