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Heating, Air Conditioning, Fridge, HVAC/Carrier Infinity Compressor Quits


I have a Carrier Infinity 15-seer, 5-ton unit, model# 50XT-A60---3. My compressor comes on runs about 30 seconds, then kicks off and throws the error code Thermal cut off in high stage. Sometimes after resetting I can get it to run, but some days it does it all day long. I have had techs out but it hasn't done it while they were here and they can't find the problem even though they see the error code in the fault history. And on the installation manual it says that it is cause by the start relay(if installed). My question is, is there one on this unit? If so, what is the part #? And if not, what else could cause this problem. I am sitting here with a $6000 unit thats 4 years old and still roasting. Please help.  Thank you.


If you still have a labor warranty , the installing Company should be able to tell if you have a start assist kit. I researched your unit but was unable to find the wiring diagram. I would get a certified Carrier Contractor or the original company or who ever you called to check with a Technical Rep. From Carrier to come out to your residence to see exactly what they would recommend. Quite possible you need to install a start kit as stated. You can send photos of your electrical section of your outdoor unit after shutting the power to the unit and removing the panel and I can tell you if you have a start kit,if your willing to do that. Otherwise I would have the contractor get in touch with Carrier and get one of their Technical Representatives to your residence. I can only speculate what your problem could be, voltage issues, wiring needs to be tightened, compressor wire at terminals deteriorated,  I do not know

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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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