How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask BillyHvac Your Own Question
BillyHvac
BillyHvac, Journeyman HVAC Tech
Category: HVAC
Satisfied Customers: 22110
Experience:  Endorsed for unlimited heating, cooling, oil burners, boilers, refrigeration, hydronics
12672042
Type Your HVAC Question Here...
BillyHvac is online now
A new question is answered every 9 seconds

I have a Bristol pn 709XXX-XX-XXXX9 compressor in a central

Resolved Question:

I have a Bristol pn 709XXX-XX-XXXX9 compressor in a central HVAC condensor. The compressor hums for a couple of seconds and then turns off as if a thermal switch is kicking in. The condensor fan is operating, and the condensor coils are clean. Is the compressor shot? Could this just be an issue of low refrigerant?
Submitted: 5 years ago.
Category: HVAC
Expert:  BillyHvac replied 5 years ago.

Hello,

 

This is a symptom of the start capaciytor being bad. The capacitor is responsible for getting the compressor going. Follow the wires to the capacitor , mark wires, remove, and take old with you to heating/cooling shop and get a new one.

 

BillyHvac and other HVAC Specialists are ready to help you
Customer: replied 5 years ago.

Thanks,

 

I have a follow up question. The same capacitor "can" also serves the evaporator fan The capacitor can has 3 terminals. One capacitor is labled as 45 micro F and the other is 5 micro F. Have you ever seen where only one of the capacitors inside the can goes bad with out the other?

Expert:  BillyHvac replied 5 years ago.

 

Yes, this very common for one or the other to go bad instead of both.

 

The only thing in common is the C terminal. They are 2 independent circuits inside.

 

Power fluctuation, power outage, hard start up...even just weak filaments can compromise the capacitor. Most capacitors (dual) that I change have only bad side.

 

Billy

BillyHvac and other HVAC Specialists are ready to help you

Related HVAC Questions