| Stormin Mormon 2005-07-24, 9:13 pm |
| As I've only worked on gas furnaces (a very few boilers) and split systems,
here is what I've seen:
At the Stat
Red -- transformer power "hot"
White -- heat
Yellow -- call for AC
Green -- fan for furnace
At the outdoor condensing unit, red and white for the contactor (which go to
Y and C on the furnace board)
--
Christopher A. Young
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"Jake" <jkelleyus@insightbb.com> wrote in message
news:B%vEe.177036$_o.140550@attbi_s71...
> Some of the wires are yellow, some are blue, some are yellow and brown.
> and yes, for all practicle purposes, most resi condensers and heat pumps
> have the control wires hanging loose and you wire nut the stat wires to
the
> contactor wires.
OK, I guess.... but I still don't like it... even if that is the SOP. I
think if it was me I'd bring the stat wires to the contactor then... put
sta-cons on the stat wires and go direct to the contactor.
Boy, these manufacturers must do everything they can to cut corners. One
of the things that is my pet-peeve on industrial control systems is the
wire numbers or color-coding not being preserved from point-to-point. It
makes things difficult to troubleshoot (-;.
As always here, I seem to be a victim of working only with larger
systems. I would 'assume' that on setups that are HP's, and dual stage
compressors, or have other features that the low-voltage controls are
properly marked and hopefully maintain some color-coding or marking
scheme that makes them easier to hookup and troubleshoot?
BTW, this brings up another point: We've been doing some controls
interfacing to larger equipment and have employed the following color
coding... which a major OEM supplied us.
(R)Red - Hot side of 24 VAC Xfmr
(C) Black - Common side of Xfmr
(Y) Yellow - Compressor Run (including OD Fan)
(W) White - Emergency Heat call on HP from Tstat
(W2) Pink - 2nd stage Heat Call
(D) White w/red tracer - HP condenser defrost signal to IAH
(G) Green - IAH Blower
(O) Orange - Condenser RV on heat pump
(Y2)Blue - 2nd Compressor stage
Some on-site HVAC people have told us it's non-standard... any comments?
[color=darkred]
> For a basic condenser, it doesn't matter... the 2 control wires go
directly
> to stake-ons that are on the contactor coil connections.
> Its 24VAC...it doesn't care which control wire goes to which side of the
> contactor coil.
> A heat pump is a little more complicated... there are more wires. :-)
I understand that... I just wonder why the heck they don't just maintain
the industry standard (or manufacturer standard) color coding?
Jake
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