Electricity is color blind. This was drilled into my head through my apprenticeship.
Fact is you all can ask for color standardization but the manufacturers will not go along with it. See Trane for explanation. One thing I don't understand is how some will go into great explanation on why T-Stat wire needs to be standard colors regardless of any variables.
However when you get into a unit (ill use the last unit I worked on as an example) a heat pump built by American Standard.
Yellow Wire (Compressor) comes into a mullex plug, comes out Yellow with a Red stripe, picked up HP switch, comes back out same colors, picks up low pressure Blue with black stripe (2 colors that go well.....) comes back out same, then loss of charge switch, solid white... Herm.. white, really? How the #$%^ does this make...
Point is, the Manufactures are having a hay day with the (Hey new guy, pick a color you want to use for Loss Of Charge... CLEAR IS MY FAVORITE COLOR)
At our Company we use this.
Red = Power
Black = Common
Yellow = Compressor
White = Heat
Green = Blower
Orange/Blue = RV
Pink = Second Stage Heat/Cool
Opposite of Needed RV color = Second Stage Heat Cool when needed.
This is our Guild Line, so we have a standard on our installed equipment, makes trouble shooting easy. Lucky for us we have been doing this from 1995 (color standards that is, not 8 wire) so we know our customers well.
Lot of good points have been made. I believe goodman has gone to a blue/pink wire for compressor. I have seen some brand equipment use gray for fan.. Some companies use black, others blue for common. There are some who have gone to international standards. Westinghouse had a line that had rv's fail to cool. I have seen black ,blue, brown, and white used for common... not to mention red! There was a real old timer who knew his stuff, who used one color for everything. He wasn't lazy or stupid( at least not as for knowing his trade), he just expected his people to know their components! If that rv failed to cool or failed to heat , you had better know it. His way was different, but he made you pay attention. You had better know where the other end of that conductor was landed and why. He built a very successful business in his day. You didn't guess or "assume" with him. It would be nice if everyone was on the same page, but they are not. I think it starts with the manufacturers, maybe I"m wrong. No matter, I will always check that breaker and use my meter.
I failed to mention the t'stats that have a common o/b terminal that requires internal programming to differentiate the rvs' mode of operation. What color there? Goes back to manufacturer.
We use a very similar system. Except the RV is always orange and therefore blue usually becomes Y2 for us and we often use brown for W2.
Originally Posted by Epicfail
I can't remember but it seems like I put in a Bard, that used like 12 conductors, some years ago. I like the pretty colors! Sometimes I feel like a phone lineman, with all the different colors.