Outside AC Won't Come On


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Old 06-05-08, 06:39 PM
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Outside AC Won't Come On

It's getting hot in here...

Outside unit won't come on. The contactor plunges (on with power, off with no power). The compressor doesn't stir. The fan doesn't turn. Inside unit is blowing air around the house.

HVAC guys serviced my neighbors (condo) unit a couple days ago, hoping they didn't accidentally do something to mine.

Unit: Ruud Acheiver 10 SEER-018 (maybe 20 years old).

Took the cover off, have a "live wire" tester. All three wires to the fan were "live" when the air was on, just the orange when it was off.

Do the compressor/fan have some type of dependant relationship which keeps one from working unless both work?

The capicitor seems to be "live".

The little board doesn't seem to be doing much.

Is it a fan, compressor, capacitor, board, fairy dust is low?

Unit heated the house over the winter. This spring, not sure if I've had the AC working yet, though I think it's blown cold.

It's getting hot this weekend. Would like to know if I can fix or just call it in.

Thanks,
Budreau68
 
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Old 06-05-08, 07:55 PM
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Check the fuse-box next to the outdoor unit.

There are two distinct sources of power feeding the outdoor unit. One is 24V, this is the one feeding the contactor coil and making it pull-in (contacts close)...which seems to be happening as per your description.
The other is 220V coming from your circuit-breaker box to the fuse-box and finally to the power side of the contactor. This second source of power seems to be missing.

I went to service a packaged unit once, on the roof of a strip mall. There were about 12 units there, serving different stores beneath. Curiously, any time one of the tenants would call for service, someone else ended up without A.C. The fuses would "mysteriously" dissapear.

Locking the fuse boxes stopped the problem.
 
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Old 06-05-08, 07:59 PM
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Originally Posted by Budreau68
Outside unit won't come on. The contactor plunges (on with power, off with no power). The compressor doesn't stir. The fan doesn't turn. Inside unit is blowing air around the house.
Ok, we're good with the low voltage side.


Took the cover off, have a "live wire" tester. All three wires to the fan were "live" when the air was on, just the orange when it was off.
3 wires?? Should only be 2 on a 220 volts system.

Are you reading power just before the contactor? L1 and L2?
and between T1 and T2?
 
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Old 06-05-08, 08:38 PM
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Clarification

Jay11J
Sorry, I mean the three wires to the fan seem to be energized when the AC is turned on inside. To and from the contactor is two wires. The whole contactor reads hot with line tester, AC on or not. Know that is is a relativly cheap tester, just beeps if it finds power, meant for keeping folks like me from frying ourselves cuz we forgot to turn off the house power before a receptacle change.

Pflor
The idea of the fuses I like. I see the fuse box, but when I open it it has a little black box, with a ring sticking out the middle. one side says on, other says off. Are the fuses behind this and I pull the ring to remove the cover? Or do you turn the ring to turn power on/off? If they took my fuses, I'd chock it up to them testing her unit to test a problem then forgetting to replace mine. Sigh...

Thanks for the replies...
 
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Old 06-05-08, 08:42 PM
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Id' get a real meter that you can read 220 volts.. You may be only getting 110 volts, so one of the use may of blown.. and the tester you got is not showing that.
 
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Old 06-05-08, 08:51 PM
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Multimeter in hand

I've got a Digital Multimeter. I'm just not good with it.do I turn it to V AC 750? The other option is 200.

Then try the posts on the contactor?
 
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Old 06-05-08, 08:53 PM
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Originally Posted by Budreau68
I've got a Digital Multimeter. I'm just not good with it.do I turn it to V AC 750? The other option is 200.

Then try the posts on the contactor?
Set it to 750volt AC and put the probe between L1 and L2 at contactor should read around 220-240 volts, if you read 110, then a fuse is blown.
 
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Old 06-05-08, 09:23 PM
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Getting Close

I can only find L1 and L3 by following the wires, no L2.

For the multimeter, I have two wires and three plug ins. which do I use?

I am happy to say I found the pull out fuse block and tugged on it to find the two fuses inside. So, I know understand how that works. Now if only I knew whether or not they worked.

Thank you for your continued help.
 
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Old 06-05-08, 09:27 PM
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Pull the fuse out again, and set the meter to OHM scale.

What does it say on the hole for the probe to plug into on the meter?
 
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Old 06-05-08, 09:36 PM
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Fuse/Multimeter

Fuses are out and in hand.

Multimeter, figured out the volt reader (how to use multimeter wiki). Plugs are V a, Com, and unfused.

So Ohms, what am I looking for there.

When I touched the volt reader to L1 and L3, I didn't get any reading, but the AC unit wasn't running either, I need to turn the AC on don't I?
 
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Old 06-05-08, 09:40 PM
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Ok, put the meter in OHM scale, and then put one of the probe on one end of the use, and other probe on other end of the same fuse.. If no changes on the scale/reading, the fuse is blown.

If you have change in scale/reading, then try other fuse..

Ignore the A/C for now, just go on the fuse.
 
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Old 06-05-08, 09:48 PM
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Wow!

Ok, Ohm readings, one fuse went from 1 to 0. I'm guessing good. Other fuse 1 to 1, no change, I'm thinking bad.

Also thinking you rock. Thanks for the help.

You think Walmart carries this part? Only thing open around here at this time. Man it's hot.

I'll replace the bad fuse and hopefully all will be good with the world. At least until the next weakest link breaks.
 
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Old 06-05-08, 09:52 PM
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You could try Wal-mart.... My guts say no, but then I never looked for them there.. May have to wait till morning when hardware store or home center opens.

Take both fuse with you, and they may have a meter/tester to check for you to make sure.
 
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Old 06-05-08, 10:03 PM
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Will do.

Walmart is closed anyways. I'll take them both to the hardware/big box, then update this thread with the results.

Thanks again. If this works you saved me at least $70 I don't have and learned me up a little too, always a bonus when doing it yourself.
 
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Old 06-07-08, 11:03 AM
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Update

Fix it! Thank you very much!

Lowes did not have a 25 amp time delay fuse.
Ace did, about $5 each. Got two, replaced both. AC has been blowing cold for 2 days!

Thanks again.
 
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Old 06-07-08, 02:10 PM
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Glad to hear you're up and running.

Make sure the coil is clear and clean.
 
 

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