Heat pump circuit breaker problems

[pinkertonpv]

About 8 years ago I installed a 6 ton heat pump at my house in north Alabama. A friend with an HVAC license helped me with the technical part. I installed the appropriate out door circuit breakers for the amperage with the appropriate wiring. I did not replace the circuit breaker in the house breaker box. The house is approximately 35 years old. The inside circuit breaker is a 60 amp to the HVAC side with a separate 60 amp circuit breaker to the heat strip side of the heat pump. I also installed a digital computerized thermostat. My friend wired and programed the thermostat. Everything worked perfectly for the next 7 years.

This past year I have been experiencing times when the inside circuit breaker to the HVAC side will trip. It usually occurs every 2 or 3 weeks and usually during moderately cold weather. The CB shuts off the thermostat. Heat pump of course will not work until the CB is reset. Thermostat and heat pump work perfectly when CB is reset. Thermostat seems to work perfectly all the time.

I believe the problem is in the CB or the thermostat. I first plan to replace the CB and see. I am a little worried about leaving the house when cold weather is coming. N Alabama is generally mild during the winters but sometimes can go into the teens for a few days. If the CB trips while I am gone, pipes may burst.

If the CB change out doesn't work then I guess I will call a technician. My friend has moved to N Carolina.

Any Ideas?

[HayZee518]

circuit breakers can weaken if repeatedly tripped. reasons for tripping are - OVERLOAD, SHORT CIRCUIT. If one or more heating elements in your unit are open, the element may be grounding out against the metal frame. 60 amps times 240 volt equals 14,400 watts. a 1 horsepower motor operating at 240 volts draws 3.1083 amps - 1 HP = 746 watts.

[dosser]

How old and what manufacture is the CB in the house? When the CB trips is it hot to the touch? Look at the wires connected to the CB going to HP, and make sure they are tight. If you are able, pull the CB and make sure the clips on the bus are not burned. DO NOT TOUCH THEM-WITHOUT TURNING OFF YOUR MAIN BREAKER AND TESTING THEM DEAD WITH A VOLT METER. Loose wiring will cause high resistance, which causes more amp draw across higher resistance, which makes heat. Residential CB are thermo operated