No control voltage

[selfel]

I have a mid '80's Coleman A/C unit that quit on me. It's up at a weekend place 3 hrs from here and I don't have access to the model no.. I had a friend stop and by and do some quick troubleshooting and the outside unit will not come on. If you close the contactor it will start but has no control voltage. I'm thinking (hoping) T-stat or transformer.

My plan is to buy both and bring with me this weekend. I've seen two tranformers for sale on this site, a 220V and a 120V primary.

Question is, without the model number would one be more likely to be the right one than the other?

I know this is a long shot but sure use some guidance.

Thanks

[Robert]

Hi,


Get some wire and terminals, wire nuts, elect. tape also.

Could be a wire chewed through by vistors underneath.


If your furnace is electric, get 220vac primary/24vac secondary.


If your furnace is gas, get 120vac primary.


Get one that is 40VA also, that way you are covered whether it is a 40VA or a 30/35VA.


Also get a 240vac/24vac coil/40VA contactor.


Where is the home located at ?


Thanks,
Robert

[selfel]

Thanks so much for the reply. It's an electric furnace so I'll need the 220V.

To get me through the weekend I had considered buying a "generic" 120V/24V transformer and wiring to an extension cord. That way I know I can force control voltage to the outside unit, either before or after the thermostat. Worst case I'd have to plug/unplug to regulate temp but at least I'd have A/C to sleep and troubleshoot the real problem (and get model/serial info).

The 240vac/24vac coil/40VA contactor you mentioned. Is that a trasmormer/contactor all in one package?

My place in about halfway between Houston and Dallas, near Centerville, TX.

[Robert]

Hi,

DO NOT wire any circuits to an extension cord.


No, the transformer is one part and contactor is another part.



If you get the transformer and contactor I stated and wire/terminals, you should be ok IF it is a low voltage circuit problem.


Will be back shortly to add price quotes for those parts and you can see them.


Thanks,
Robert

[selfel]

Is the contactor you're referring to in the Coleman unit inside? Or the contactor on the outside unit?

You don't like my extension cord idea?

[Robert]

Contactor is outside, it's what your friend pushed in to start unit.


No because I doubt you like fires.




Thanks,
Robert

[selfel]

I see. Since he confirmed no 24V at the contactor I just assumed that it was not the culprit.

Is the 3300-3861 transformer the one I need? Or will I need my Model/Serial number to confirm?

If that's the one, could I get one to Houston by Friday afternoon?

[Robert]

Hi,

Will need furnace and outside condenser model numbers to get exact replacement.


However, can select parts that will work for all specs if needed.


You stated your friend pushed in contactor to get it to work. That doesn't verify whether there is 24vac at contactor coil.


Contactor can have 24vac at coil and be bad.


Too late to get shipped today, so shipping tomorrow would require overnight to get there by Friday.


That would be costly for those parts. If you have an address there, it may could get there by Saturday.


Will be back on later tonight and give all needed info.



Thanks,
Robert

[Robert]

Hi,

After rereading your post, IF he actually tested and had no control voltage at coil, contactor should be ok, but as they fail every 3-5 years, would be wise to have with you.


Contactor #024-26018-000 @ $24.00

Transformer #3300-3861 @ $20.25


If these two are not exact replacements, should be fine for your systems.

http://www.mobilehomerepair.com/ColemanAC.html


Wire and terminals here :

http://www.mobilehomerepair.com/FurnaceElec.html


All can be ordered through PayPal at those links or by calling toll free after 9AM CST to 1-877-263-7860 and charging to Visa or Mastercard or have a PayPal Invoice sent via email for payment.


Best to call and speak with Mark for overnight shipping.


Thanks,
Robert