AboutHoward Livingston Expertise Can answer questions on electrical control circuits, power supply,airflow & distribution, electrical components,refrigerant problems,gas, electric & propane furnaces.No boiler or refrigerator or oil fired furnaces experience.Just HVAC questions please.
Experience 35 years experience in residential & light commercial repair & installation.
My central AC worked great until last Tues. afternoon when during the sweltering
heat of mid-afternoon, we noticed the blower was on w/o any cold air coming from the
vents. I assumed PG&E had shut us down temporarily due to load management under the Smart
AC Program. Next day we called PG&E and the technician tried to determine which breaker
the AC was on. By reading the unit's requirement of at least 33 but not more than 50, he
figured the circuit with the 50 amp breaker must be the subject circuit, and the breaker
might be bad. He turned it off and on a few times then retested the AC by turning it to
COOL inside at the thermostat. Prior to this, however, he tested the fuses found in the dedicated box with
the master switch for the AC unit, and he said the fuses were fine. When still no cold air
came out of vents, he said we must have a bad 50 Amp breaker that we needed to replace at
our expense. We did so that afternoon. Still no cold air when the system was retested. HW
store guy said breaker we were replacing looked perfectly good to him. The handyman that
replaced the breaker set and reset the breaker after wiring in the new one. We then
called PG&E and they sent someone back who said he'd never seen anything like it. No
power was getting to the unit except for the low amperage power. The AC unit hums when the
thermostat contol is set to COOL, but the unit does not come on and begin cooling
Don't know what to do next. PG&E say it's not their problem. System worked fine until
they shut it down to manage load last Tuesday."
Answer Oh Jennifer, never saw so much ineptitude in one place !! The guesswork on the 50 amp breaker shows that bigtime. Breakers can be tested good or bad right where they are with a voltmeter. No guessing . The trouble smacks of a contactor with burned points that won't make on a call for cool. A common problem. Locate the contactor in the outside unit. With a screwdriver press in the points. Does it run ?? Thats the proof of the problem. If thats not it send me a follow up. Those Smart meters are just trouble ahead. Wrap aluminum foil over them to deflect the signal if you want to be nasty. Your sentence is deceiving "but the unit does not come on and begin cooling." ??
Now its my turn for a question Why was it you, Jennifer asking the question ?? Have a husband ??? friend ?? I ask because a great amount of questions are asked by a female. I'm curious. I live in Texas, by the way.
