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View Full Version : Central air -thermal protection for compressor


pardriver
Aug 12, 2009, 08:30 AM
Hi,
I have a 30 year old magic chef 2 ton unit.the condenser fan failed and I replaced it and capacitor. The unit now works fine except that I have had to bypass a limit switch(l 118-15). This switch has 3 wires coming from it and looks like a defrost thermostat. No model number,no schematic. This switch is located inside,on the top of condensing unit,right where the hottest refridgerant would come in to the condenser.
It seems that this switch would protect the compressor in case the fan quit by turning off the compressor.no one seems to have a switch with 3 wires and with the new fan motor there were only 4 wires instead of 5.
Since the compressor is thermally protected,should that be enough?

Thanks---tim

hvac1000
Aug 12, 2009, 11:27 AM
That might have been for the 2 speed design of that old system. I believe Magic Chef had a tempersture control that would allow the fan to run at low speed and when the condenser got hot it would switch to high speed. I would just bypass the switch since a unit that is 30+ years old is running on borrowed time. My oldest condensing unit at my house is 31 years old and I feel I will be replacing it soon. They sure do not make them like they used to.