Old a/c no C-wire


Old 11-30-17, 02:02 PM
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Old a/c no C-wire

I have a really old ac probably before there was a C wire. I have other hook up as you see i the pic.
O-W-X-Y, Can any one of those be uses as a C wire?

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Last edited by PJmax; 11-30-17 at 03:30 PM. Reason: reoriented and labeled picture
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Old 11-30-17, 02:36 PM
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I believe the B screw is the C that you are looking for. It has a wire that goes to the outside unit. You can put two wires under one screw.
Old 11-30-17, 03:31 PM
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That must have been from the York days but I don't remember using the B as C.
In this case though...Astuff has nailed it.

I believe that posted model number is just for the electric heat section..... not the air handler itself. 10kw heatstrip(s)
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