AC not working

[Mike Humble]

None of my AC units work in either heat pump or AC mode.  All worked yesterday.  Have good power 120v to both legs.  Tried under gen power and no go.  Circuit breakers have been reset.  Thermostat appears ok.  Furnace works under electric power.  Any ideas?
Mike

[Richard Davis]

Mike

I would start by taking the cover off the circuit breaker box (mine is in the bathroom).  Using a VOM (Volt, Ohm, Meter) set to a scale of at least 120 volts AC, test both sides of the circuit breakers for your air conditioners (VOM red lead to circuit breaker connection (black wires), VOM black lead to ground bus (white and bare wires)).  You should have 120 volts +/- 10 volts on each circuit breaker.  If you have no voltage in this box, then you must trace backwards to see where it is being lost.  Considering your description, I would suspect that you have lost the ATS (Automatic Transfer Switch) where your shore power supplies and generator supplies come together.  If you are not comfortable testing live AC power lines and knowledgeable about appropriate safety precautions, then I would leave testing the ATS to a licensed electrician.  Good luck.

Richard       

[Mike Humble]

Have 120 v or so to both circuit breakers.  Black to ground and black to white.  With breakers off no voltage.
Mike

[Steve Huber Co-Admin]

Mike,
Your AC voltage is probably OK as none of the units are working. If the reefer works on AC and the AH also does, I suspect both legs of the transfer switch are OK. Does the Fan function work on the units? if so they are definetly getting AC. Were you in cold weather last night with the heat pumps running? Is it possible the units froze up?
Steve

[Mike Humble]

Problem solved.  Operator error.  You can't have one zone on furnace and another on AC or heat pump.
Mike

[Bill Sprague]

Problem solved.  Operator error.  You can't have one zone on furnace and another on AC or heat pump.
Mike

Never admit to "operator error"!