Int. Comfort ProductsNAC236AKA1 buzz every 10 seconds

[mosleyh]

My main floor A/C consists of a TempStar DC90 blower/furnace unit inside and an International Comfort Products NAC236AKA1 codenser unit outside. I noticed when I got home today that the lights in the house would dim for about 1 second every 10 seconds or so. When I went out to the compressor units (upstairs one is smaller, but same make) they were both running, and cooling properly. The downstairs one was making a buzzing noise at roughly the same interval as the lights were dimming. This happened for roughly an hour after I got home, then stopped.

When power is removed from the compressor, the lights stop dimming.

I live out in the sticks a bit, and this was happening right around dinner time, which makes me wonder - Is this cause or effect? Could the power coming in from the pole cause this if it were low, or is my A/C headed toward a failure?

 

Thanks

[RegUS_PatOff]

[user=39340]mosleyh[/user] wrote:

... The downstairs one was making a buzzing noise at roughly the same interval as the lights were dimming. This happened for roughly an hour after I got home, then stopped...

Disconnect the power to that unit to see if the lights stop dimming.

[TOPPS Appliance Service]

Could be time for a hard start!!!

[mosleyh]

[user=3641]RegUS_PatOff[/user] wrote:

[user=39340]mosleyh[/user] wrote:

... The downstairs one was making a buzzing noise at roughly the same interval as the lights were dimming. This happened for roughly an hour after I got home, then stopped...

Disconnect the power to that unit to see if the lights stop dimming.

It does stop it. Now what?

[mosleyh]

[user=39254]TOPPS Appliance Service[/user] wrote:

Could be time for a hard start!!!

Forgive my ignorance (That's why I'm here - to learn) but a "Hard Start"?

Please 'splain, Lucy.

[Pegi]

Sounds like your compressor is trying to start but cannot for some reason, you could have a compressor that is locked down, a compressor that has a bad start capacitor or a compressor that is grounded.....need to have someone check to see why the compressor is not starting..if you have one that is getting hard to start a "hard Start" device will give it a boost to help it start, but this will not help one that has a bad capacitor or is grounded...or is locked down...

[mosleyh]

The A/C is cooling properly, though. The intermittent buzzing/dimming is happening while it's running. Sorry if I wasn't clear about that.

[Pegi]

Well, I did not know that, so I do not have a clue then what the problem might be...:?

[mosleyh]

Update-

Now it isn't cooling anymore. The fan on the outside unit is running, and the lights in the house still blink when the unit's on, but there's no longer any condensation on the pipes going to the unit, and the air coming out of the top is cool, not warm as it should be.

 

I've placed a service call. . .

[mosleyh]

Diagnosis was (from the repair ticket)

"Scroll compressor locked down - will replace compressor"

So the buzzes and dimming lights were somehow related to the death throes of the compressor.

The odd thing is that from the time it was cooling OK to the time it wasn't, the dimming every 10 seconds was constant. It may be that it finally died completely after having been turned off for 24 hours+ - I wasn't at home when the technician visited.

 

All I can say is that I'm very thankful for the AHS warranty right about now. . .

[TOPPS Appliance Service]

If you look at your LRA [lock rotor amps] on the nameplate you'll see how many amps that puppy was pulling with a tied up compressor. :shock: