Where is C-wire

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Glenn14
Posts: 7
Joined: Sun Oct 25, 2015 10:58 am

Where is C-wire

Post by Glenn14 »

I have a EWC-OR-6 Ultra Zone controller panel (with 4 heating/cooling zones). I want to connect a Honeywell wifi thermostat but it requires a C-wire. I have run a spare wire from the thermostat to the zone controller, but can't figure out where to connect it (don't want to guess wrong).

Honeywell says it must pair with the R-wire to give power to the unit. Which terminal should I connect to?

Attached is a picture -- hope this helps.
IMG_2395.JPG
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Paul Z.
Posts: 216
Joined: Thu Dec 08, 2011 3:05 pm

Re: Where is C-wire

Post by Paul Z. »

We are suggesting replacing that board with a new NCM-300. The OR-6 is a early board and will cause problem trying to wire, best is to change board.
Glenn14
Posts: 7
Joined: Sun Oct 25, 2015 10:58 am

Re: Where is C-wire

Post by Glenn14 »

I was hoping not to have to go that route. I realize the thermostat would not control the heat/cool/fan functions -- I would still use the master switch for that. Is there any chance of finding a suitable c-wire connection using the existing panel?

Thanks!
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