Help me fix my condo A/C!

[82DMC12]

Hey guys,

It's the long weekend and my A/C isn't working at my condo. It was working yesterday morning, then by evening I realized the indoor fan/furnace had been running a long time and it wasn't getting cool. Went outside and found the outdoor unit is quiet. No compressor and no fan running. Checked the breaker, made sure thermostat was calling for cooling, also unplugged and reseated every connection I could find. Nothing. When I press the compressor contactor in, the compressor starts and sounds OK. Any ideas? I have a multimeter but I really only know how to use it for DC. I have zero experience in AC except I know how to stick the prongs in a socket and make sure it's live :-)

Last year the A/C stopped working and someone came out and replaced the capacitor. It was bulging out but the replacement one appears to be OK from the outside.

Here are some pics and the last link is the service manual which gives sequence of operation. If I knew how to use the multimeter correctly without killing myself I might be able to figure this out. Because of the long weekend I doubt I will be able to get anyone over here until Tuesday without paying up the #$%^^^

Any ideas?!?!?!

2012-09-02_09-40-34_920.jpg2012-09-02_10-25-42_27.jpg2012-09-02_10-26-05_251.jpg2012-09-02_10-26-11_224.jpg2012-09-02_10-26-16_276.jpg

https://docs.google.com/open?id=0B2m...3gyOFRXNmlqT2M

[DniveK]

if the inside unit runs but the outside unit dont run, its either disco at the breaker disconnect outside by the unit, or the cap is probally blown again. Pull the cap and put it on a meter, or take it to an Electrical supply house like Grainger and test/replace it. Probally cost you a whole 16$. The AC guy will proablly charge a min 150 for the same job if not more. See if you can find the specs on what cap is suppose to be on the unit it may have been previoulsy replaced out of spec.

By the way, that coil looks really really dirty. You should get some coil cleaner fromm Home Depot and spray that thing down and hose it off.

[Bitsyncmaster]

Some units have a shut off if the condensation drain backs up. Look at the inside unit and see if it's full of water in the pan.

[Spittybug]

When I press the compressor contactor in, the compressor starts and sounds OK.

Can you elaborate on this? Is it a solenoid switch? If you are mechanically able to close a contact and get the unit to run, then determine if the mechanics of closing that switch work outside, if so, then you are now moving up to the control signal... your meter will help you here. Many times these wires are solid not stranded and can break from vibration.

[Dangermouse]

+1 on Bitsy idea about the condensation pan.

If the compressor starts when you press the contractor then your capacitor is OK. You are missing something in your control circuit which is usually a 24vAC circuit. Start at the thermostat and make sure you have 24V on the wires between the thermostat and the outside unit. I dont recall the colors but you can see then at the outside condensor ; they are the really small ones Download the thermostat manual if you don't have on.

If you have voltage leaving the thermostat and not at the condensor, then you have a break in the wire, usually outside where someone has stood on it.

Some systems have a low pressure switch in the circuit with a red reset button. It is located in the outside condensor unit If may have accidentally tripped or you may have a leak.

Good luck

[82DMC12]

Hey guys, well I took another look and the pan was totally dry. I had +24 to the low pressure switch and to the other side of the contactor. I found the red button Dangermouse mentioned and when I pressed it in, I could hear something reset. I turned the disconnect back on and it started working!

So I'm guessing there's two reasons why that switch would have tripped - either just a fluke/accident or I'm getting low on refrigerant. This thing takes R22. Is that refrigerant still readily available for service techs? I do have an A/C manifold gauge set. I could possibly put a shot in since I do have the pressure scales in that service pdf I posted.

Thanks a ton, I was starting to stress out over how much it might cost to replace the thing in worst case!

I'll let the A/C cool down to the thermostat set point and report back if it makes it!!

Andy

[Bitsyncmaster]

R22 runs over $60 lb. New units now use R410. There is a replacement for R22 I think you can buy online that is much cheaper. I was going to get some because my downstairs unit has a slow leak. Maybe you just got a power glitch and that kicked the reset breaker.

[Dangermouse]

Is there any reason why one could not hard pipe a set of gauges?

I need to upgrade one of my units and was wondering whether I could get a HP gauge and a LP gauge installed, or would the act of adding two extra connections increase the likelihood of a leak (much like our fan fail relays)