Heating, Air Conditioning, Fridge, HVAC/Re: Short Cycling motor


Joe sorry to bother you. I need to clear things up. In a email to you, earlier today, I mentioned a problem with a evap motor short cycling. That short cycling motor is actually the blower fan motor. It (fan motor) works normally when the tstat switch is in heat mode or in the fan only mode. However, when the tstat is in the cool mode, set for cooling, the outside condenser fan and compressor operate normally. The blower fan motor short cycles, running for 1 to 2 seconds and stops. The fan motor tries to restart again for 1 to 2 seconds and repeats. Sorry for the earlier email. I hope this clearly states the symptoms. thanks for any help you can offer. My hvac unit is TempStar. Unsure of the size, capacity, model number.


Try putting the fan switch to On and run in A/C mode , does it still work ok ?   To me if you have the fan in auto and call for A/C you would need to find the fan relay and find the fan relay 24 volt ac coil power to see if your dropping out the 24 volt ,if you are you need to find why, if you are not dropping out the 24 volt and your blower fan still cycles off/on then you need to find the power 120 volt ac feeding the blower motor in cool mode to see if your power is dropping out, if power is not dropping out feeding your motor then you have a bad motor. Remember in heat mode you may be running on a different fan speed than cool. So your motor windings is different. Doubt it's your capacitor as there is only one used for heat or cool speed and it clearly runs in heat and fan ON mode. So to me your losing either low voltage 24 volt ac to the fan relay in cool mode or your losing 120 volt high voltage to the motor during cool mode. Look at the wiring diagram to find the fan relay 24 volt coil and find the two 120 volt power voltage (120 volt ac ) feeding the motor during cool mode

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40+ years diversified experience.An HVAC/Refrigeration Self Employed Contractor since 1986. NATE Certifield. Answer questions pertaining to Residential and Commercial Air Conditioning , Warm Air Heating, Heat Pump systems.Mechanical and Electrical troubleshooting of these systems.Be as detailed as possible when describing problem.Packaged unit or split systems.No appliance questions.


Installation and Troubleshooting, Mechanical and Electrical, in following areas, Refrigeration ( Walk In and Reach In Coolers and Freezers ) Commercial Roof Top and Packaged Heating/Cooling ( Natural Gas,Propane, Electric, and Heat Pumps ) Computer Room Air Conditoning Systems,Commercial Residential Packaged and Split Systems Air Conditoning and Heat Pumps.Warm Air Oil , Natural and Propane Gas Heating systems.

Graduated from Private Technical School in 1975. An HVAC/Refrigeration Contractor . Have Unlimited Heating/Piping and Cooling Contractor License.Limited Sheetmetal Contractors License.NATE Certifield. York Certifield Master Heat Pump Technician 1986. Served 33 years combination Active Duty Air Force , Air Force Reserves and Air National Guard in the HVAC/Refrigeration Shop/Mechanical Shop. Troubleshooting/Installing HVAC/Refrigeration Equiptment Worldwide. Retiring in 2003 as a Senior NCO ,and a Mechanical Superintendent.

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