Wednesday, March 12, 2014

switching-1-pole-contactor-to-2-on-ac-unit



I have read thru some old threads on this subject, and really want to be sure what I need to do. I have a split York AC unit in my place here in Mexico. The single pole 40 amp contactor 24 volt coil is toast and what is readily available, is the 30 amp,only. The 40 amp are the two poles.
Some responded that a 2 pole should not be used as a constant current was needed on one side of the contactor for the heater on the compressor. Do AC,only,units have heaters?
In another thread, someone stated that #6 wire could be used to jump the lugs on the side that did not have the pole on the old piece. In the same thread, another responded, that a two pole was fine, making no reference to jump the lugs.
So, based on all the above, does the two pole contactor need any special attention if all four lugs on the top are wired back on the AC unit as taken off or will the now opened side that was always closed keep the compressor from kicking in?
Thanks,
Rich

Since your home is in Mexico I wouldn't think you would need to worry about the crankcase heater. How cold does it get where you are ?

The lowest temperature that it may get during the year is about 65 degrees. However, if the humidity, is way down as it is November thru April, the AC is not turned on until the outside is about 85 degrees in the early afternoon. In the evening, the AC is turned off as the breeze comes off the bay. May thru October, the humidity climbs and at which, the outside temp during the day will be as high as 85 to 95 and the evenigs cooling to any where from 85 to 75:if the evenings are any 80's or high 70's, the unit will be left on, at which time it will cycle on and off. In essence, the compressor is exposed to a long period of warm air before it is manually turned on.
Thanks,
Rich

Id just say dont worry about it. At 65o down there freon sure wont try and migrate to the compressor. With units that do have heaters on them .They will say turn on 24 hr before you run them. You sure dont need that there.
The single pole 40 amp contactor 24 volt coil is toast and what is readily available, is the 30 amp,only. The 40 amp are the two poles.
Stay with a 40 amp if thats whats on there. You can go to one pole or the two pole. The units with just the one pole contactor is cause the maker is saving $$$ cause the points have silver in them.
ED

Ed,
Thank you for the help and in my case, why a two pole contactor appears feasible to use.
As to the use of the #6 wire jumper that I mentioned in my original post, is this ok to do if the current is needed for the compressor heater if other climate circumstances may dictate it? I'm sure others that have seen that post,too, wonder if the comment is practical.
Rich

why a two pole contactor appears feasible to use.
It will kill both legs of power to the inside of the unit. With one that just kills or opens one leg only. there always is 110V in the unit even if it is not running.
Just forget about the heater are as called crankcase heater .
I think you said you had 4 ton units That call for a #6 wire and a 45 amp breaker.
ED

I am in a similar situation. I baught the 2 pole contactor instead of 1 pole. Checked with my A/C manufacturer that I can use it. My problem is that i am not a professional and I do not know substitue a 2 pole contactor where I used to have a 1 pole contactor. It is weekend, the shops are closed that sell HVAC parts, any help would be highly appricated.
Thanks in advance.
Originally Posted by Ed Imeduc
It will kill both legs of power to the inside of the unit. With one that just kills or opens one leg only. there always is 110V in the unit even if it is not running.
Just forget about the heater are as called crankcase heater .
I think you said you had 4 ton units That call for a #6 wire and a 45 amp breaker.
ED

if you want to stick with a single pole setup and actually change nothing, just use one pole of the contactor and leave the other one empty.

Originally Posted by nap
if you want to stick with a single pole setup and actually change nothing, just use one pole of the contactor and leave the other one empty.
Hi Nap,
I actually want to use the 2 pole contactor now. My current one was a 1 pole contactor. What should be wiring look like for a 2 pole contactor? I am posing the photo of my current 1 pole contactor and the photo of the contactor i am trying ot use to replace the existing one:
Current burnt one:-
New one:-

Oh, so now you want to do things differently.
Just kidding.
So, I see 3 wires on the load side of the contactor (the side that is feed through). WHere do they go?
(trying to figure out if sonething actually needs to be hot all the time in some way for whatever reason)
btw: that brown or whatever colored wire on the terminal looks pretty toasted. Be sure to cut away any overheated sections when repairing.

Originally Posted by nap
Oh, so now you want to do things differently.
Just kidding.
So, I see 3 wires on the load side of the contactor (the side that is feed through). WHere do they go?
(trying to figure out if sonething actually needs to be hot all the time in some way for whatever reason)
btw: that brown or whatever colored wire on the terminal looks pretty toasted. Be sure to cut away any overheated sections when repairing.
ok, I took some more photos as well as labled the orginal one. Hopefully the setup is now more clear.
photos:-
Rest of the photos:-

I dont know of anything in a unit that need a hot leg all the time. The Mfg. use just one contactor cause it cost less. The
crankcase heater if you have on is on the hot legs comeing in and is on all the time. What I think I see that is bad bad is that aluminum wire????? comeing in that has no paste On it at all

i am begining to think that i should get a pro in to fix the wiring... in the meantime, if i understand you correctly , I can use the exact same wiring for the 2 pole contactor? The only difference being now now 1 pole is not hot wired?
btw, could you elaborate on the paste for Alimunium wire? I am very new to this....
Thanks

I do see some connections on the line side of the contactor, as Ed said, that would be anything that needed hot al the time.
Now to the aluminum wire?
First, is it aluminum or tinned copper?
If aluminum, the terminals MUST be rated for aluminum wire or don;t use the aluminum or get a contactor that has alum. rated terminals.
Now, Ed said something about paste. Although there is no code requirement for No-Ox or some other oxidation preventing material, it is a very good idea to use it as it does some good and prevents oxidation which itself can cause a loose terminal which can cause all the problems you have right now.
don't forget to fix that brown wire. with the close up, I can see the terminal is not crimped on properly and that can also cause a hot wire which the melted insulation could be a result of.

when using no-ox, be sure to brush the aluminum clean before applying.
and yes, the wiring is the same.

Originally Posted by nap
I do see some connections on the line side of the contactor, as Ed said, that would be anything that needed hot al the time.
Now to the aluminum wire?
First, is it aluminum or tinned copper?
If aluminum, the terminals MUST be rated for aluminum wire or don;t use the aluminum or get a contactor that has alum. rated terminals.
Now, Ed said something about paste. Although there is no code requirement for No-Ox or some other oxidation preventing material, it is a very good idea to use it as it does some good and prevents oxidation which itself can cause a loose terminal which can cause all the problems you have right now.
don't forget to fix that brown wire. with the close up, I can see the terminal is not crimped on properly and that can also cause a hot wire which the melted insulation could be a result of.
Thanks again for your help! How do I tell if it is aluminum or not? What is a good place to pickup No-Ox from? Home Depot?
thanks again for your help!!! Thank you Thank you Thank you!

scrape it with a knife or cut a bit off the end. If you see copper, then it isn;t aluminum but tinned copper. If you are familiar with both, simply bending it would tell you as aluminum is softer.
as to no-ox; I believe you can get it at the big box home stores. If not, it is available at any electrical supply house.

Its hot, my pregnant wife is mad and I the AC wouldnt start! I was couldnt strip the wires or clean them up as it was dark, but was able to put the contactor in. Now the freaking AC does not want to start!!!
my backup plan (the weather channel with a cold front coming in this weekend) has failed me!!!!
Guys, what could be wrong? Is it the wires I didnt fix tonight?
Do you folks know of a service which would come out on a Saturday? I am desperate now, for if it cannot be fixed, im off to buy portable indoor unit(s) tomorrow. (btw, i am in Austin, TX)
Originally Posted by nap
scrape it with a knife or cut a bit off the end. If you see copper, then it isn;t aluminum but tinned copper. If you are familiar with both, simply bending it would tell you as aluminum is softer.
as to no-ox; I believe you can get it at the big box home stores. If not, it is available at any electrical supply house.

In a ciy like Austin, TX Get the phone book .Ill bet there are some 24/7 AC companys.

Originally Posted by Ed Imeduc
In a ciy like Austin, TX Get the phone book .Ill bet there are some 24/7 AC companys.
Thanks ED, I looked up online YPs and that didnt help too much. I will strip the wire and then call around tomorow morning.

They say 24/7
http://www.polarac.net/






Tags: pole, contactor, unit, pole contactor, Originally Posted, aluminum wire, side contactor, aluminum tinned, aluminum tinned copper, crankcase heater, side that, single pole