Thermostat seems working fine, it triggers correctly and there is air coming out of the air duct. But the air is not cool, it turns out the outside air conditioner is not running.

Checked the power control in the basement, no circuit breaker is triggered. There is no labeling though. Is it true that the breaker for air conditioner always occupies two slots?

Upon inspecting the outside unit, I found there is a disconnected wire. see picture

Is this control wire from thermostats? It doesn't seem to be since it only has 2 wires instead of 4.

What is the wire? I have another same unit(upstair/downstair), which does have a similar wire connect into the disconnect box. But this wire in picture is kind of flat which the wire in another unit is kind of round.

So I thought I can open the disconnect box to take a look. Normally the front of the box can be opened from the bottom, however seems my box is a little bit different, it should be open from the right side based on the location of the anchor for the lock.


In order to open front cover from right, I need to open the top cover first? I removed the two screws from the both sides of the top cover.


However it seems I can still not able to open the top cover or front cover. The box was pained when contractor painted the wall, so I've already scratched those paint.

Running out of ideas... could someone help me...
1) what is that wire supposed to be?
2) how to open the cover for this kind of disconnect box?

Thank you!

 

Yes thats the stat wire. Only 2 wires needed.

 

That disconnect open's from the bottom.

 

Turn the circuit breaker off , that supplies the outside / condenser unit . Yes , they are almost always feed from a 2 pole circuit breaker ( or 2 fuses ) . Unless , possibly if it is a very small unit .

The indoor unit / furnace is usually feed from a 1 pole circuit breaker , unless it has electrical resistance heat . In that case , a 2 pole circuit breaker .

Best thing is to replace the damaged low voltage wire to the condenser / outside unit all the way back to the furnace / indoor unit . If that is not practical , replace it from the condenser to , it looks like the disconnect . ( Which I would not wire it the way it is . I do not mix line voltage wiring with low voltage wiring . )

Do you have pets or vermin that may have chewed the wiring . Or a weed-eater ?

God bless
Wyr

 

The thermostat wiring is rarely run thru the electrical disconnect. It more than likely came thru the hole in the wall next to the disconnect. Look in the basement for the other half of the wire.

 

Thanks all, I managed open the disconnect box and PJmax you are right, there is no indication of the that wire connection in the box. It should be from that whole. I will look into the basement.

It guess it was done by some animal. There is a fence around the the whole air conditioner area that people can't get in without open the door on the fence.

Where can I buy the thermostat wire? Is it just alled thermostat wire?

thanks.

 

I would seal the space around those refrigerant lines after pulling new wire. If a rodent chewed through it one it will happen again unless you seal it with silicone or something similar..

 

looked basement and find this wire. It reads "ITT 18/2 SPT-1", see below. It is a wire from the furnace unit to the outside AC unit. It doesn't seem to be thermstat wire, what wire is this? I tried to find it in homedepot, the closest can be found is 18/2 SPT-2 lamp wire, but I'm not sure if this can be used to connect the broken "ITT 18/2 SPT-1" wire? Need more advice... Thanks!

 

Lamp wire doesn't have the protective jacket required. Depot, as well as most home improvement stores, carry the thermostat wire prepackaged.

Cerrowire 50 ft. 18/2 Thermostat Wire - Brown-210-1002BR - The Home Depot

 

Thanks PJmax! I will try to get it from homedepot/lowes tomorrow.

 

I was looking at Depot store stock and the store near me sells it off a bulk roll for around .20 a foot.

 

when you say "depot store", is it homedepot?

I was in homedepot this afternoon. I showed the wire guy there that I need this "ITT 18/2 SPT-1" wire which connects from furnace to AC, but he wasn't able to find one. I think the that store probably doesn't carry the wire you linked in the previous post. This item doesn't have the option to do stock pickup, so I assume it is not available in store?

I found lowes has this Shop 50-ft 18-AWG 2-Conductor Thermostat Wire at Lowes.com and it is available to pick up at my local store.

It is 50ft roll for around $8. I only need 10ft or so but if it doesn't sell by the foot, I will just buy the 50ft roll.

I don't know any other local store that sell this kind of stuff. I have a loca acehardware but it is small compare to homedepot/lowes.

 

Yes......Depot = Home Depot.

You just need two conductor #18 thermostat cable or doorbell cable.
The writing on it is not important.

You may find it in your local hardware.

 

It is ~ 24 VAC so almost any type of 18/2 copper cable will work .

If you can gently pull the wire , back and forth , through the exterior wall . I would replace it all the way from the condenser to the furnace . 50 foot will likely go all the way ?

Tie on to the old cable , securely w/o leaving a big knot to hang up on . Use the old cable as a pull cable .

Then I would install it in LiquidTight / SealTight flex conduit . To protect it . And do the same with the power wiring to and from the disconnect .

AFC Cable Systems 1/2 in. x 25 ft. Non-Metallic Liquidtight Conduit-6002-22-00 - The Home Depot

You would need a few connectors

Search Results for liquidtight connector at The Home Depot

If you can not pull new cable , splice on to what is left of the old cable , outside and water proof the splice .

God bless
Wyr

 

Thanks for the response, Wyr.

replace all the way seems lot of work to me since the ceiling of the basement is kind of sealed, so need to open lot of boards.

I opened the cover of the condenser and found that this wire connect to one blue line and one yellow line(see red mark in below picture). If I don't replace the whole wire from condenser to furnace, but just get a few foot and connect to the existing wire, how do I know which wire connects to the blue and which wire connects yellow? If the connection is wrong and then turn on the AC unit, will it cause any damage? Or if it doesn't work I can just switch the connection to yellow and blue?

Thanks!

 

There is no polarity as that is 24v AC. You can connect them in any order.

 

got the wire and connect it, AC working fine now.

thanks all of you!!

 

Good job.

 

If the wire in the basement is inaccessible , I understand not replacing that part .

Make sure your splice from the old cable to the new cable is water tight .

I still advise you put the cable in LiquidTight , when it is exposed , outside . To protect it & keep it from happening again .

Glad to hear you got it running again .

God bless
wyr

 

Thanks for the reminder Wyr.

Actually I've made the connection point inside the basement so it will not be exposed outside.

I'm planning to put some kind seal to the hole in the wall (see picture that PJmax put a red arrow). Is this a good idea? If so what kind material is best? It should be easy to open it up again when necessary.

 

Duck seal will not last forever , but is easy to remove . Silicon caulk will kast a long time , but not as easy to remove .

God bless
Wyr