# Wiring colors on control panel



## ponyboy

What I've been using in our buildings

Red- AC control power
Blue- DC control power
Yellow- fed from remote source


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## dronai

Similar here. Blue for DC, Red for 120V control, Yellow for outside source


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## oliquir

ok so everything DC (input, output, 0V 24V ) have the same color inside the panel? 
(im not talking about wiring between panel and devices)


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## dronai

oliquir said:


> ok so everything DC (input, output, 0V 24V ) have the same color inside the panel?
> (im not talking about wiring between panel and devices)


DC negative-Blue with white stripe or white with a blue stripe. That I've seen.


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## Big John

Black - Line power
Red - Reduced voltage controls
Yellow - Alternate source
Blue - Ungrounded DC
White - Grounded conductor (marked with stripes per system)

Check out NFPA 79.


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## MTW

Red and white for AC I/O, all blue for DC I/O, and numbered black for motors.


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## lefleuron

Black for motors or anything with a potential above 120.

Blue for all DC, in or out.

Red for 120, white for 120 common.

Unless you are using EU control devices, then its Brown for 24V+ and Blue for 24V-.

And nobody seems to care about voltage from a different source here, you MIGHT have a sticker or a magic marker scribble.

Just use Black, Blue, Red, and White and you will be fine. Yellow if you are using separate sources inside the same panel would be a nice thing.


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## SteveBayshore

What about field devices. How many guys here try to correlate DC field cabling colors with AC wiring and make the black in a black and white pair the positive and make the white the negative?
Next when you come across a black and red pair the black now becomes the negative and the red is the positive.:thumbsup::thumbsup:
Now half of the job has the blacks as negative:thumbsup: and the rest of the blacks are positive. Great for troubleshooting.
Most of the shielded cables that we come across have a black as one of the colors in each pair; make it the negative, next color, no mattter what it is, will be the positive.:thumbup:


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## glen1971

SteveBayshore said:


> What about field devices. How many guys here try to correlate DC field cabling colors with AC wiring and make the black in a black and white pair the positive and make the white the negative?
> Next when you come across a black and red pair the black now becomes the negative and the red is the positive.:thumbsup::thumbsup:
> Now half of the job has the blacks as negative:thumbsup: and the rest of the blacks are positive. Great for troubleshooting.
> Most of the shielded cables that we come across have a black as one of the colors in each pair; make it the negative, next color, no mattter what it is, will be the positive.:thumbup:


Colors mess people up.. Eliminate all wire colors, go with black and number each wire.. Shielded pairs and triads would be easy - Wire #1 is +.. 2 wire devices with x-link (or thhn) would be the same.. 
When I do industrial buildings in conduit I don't even try to pull circuits by phase color any more for the AC.. Controls are all black wire (12 volt, 24 volt or 120 volt)... Belden are terminated as per the client preference, white or black positive.. If there is no spec, or if it is new and not spec'd - white is positive..

Just my 2 cents...


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## ScooterMcGavin

glen1971 said:


> Colors mess people up.. Eliminate all wire colors, go with black and number each wire.. Shielded pairs and triads would be easy - Wire #1 is +.. 2 wire devices with x-link (or thhn) would be the same..
> When I do industrial buildings in conduit I don't even try to pull circuits by phase color any more for the AC.. Controls are all black wire (12 volt, 24 volt or 120 volt)... Belden are terminated as per the client preference, white or black positive.. If there is no spec, or if it is new and not spec'd - white is positive..
> 
> Just my 2 cents...


You mean like this. Control wire is the same color and same size regardless of system or voltage. You really have to watch what you're doing and read the labels.


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## KDC

Honestly, anything that makes you refer to prints and think can't be all bad. 

I'd rather see things properly labeled and one colour than a rainbow and guess what's what.


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## oliquir

SteveBayshore said:


> What about field devices. How many guys here try to correlate DC field cabling colors with AC wiring and make the black in a black and white pair the positive and make the white the negative?
> Next when you come across a black and red pair the black now becomes the negative and the red is the positive.:thumbsup::thumbsup:
> Now half of the job has the blacks as negative:thumbsup: and the rest of the blacks are positive. Great for troubleshooting.
> Most of the shielded cables that we come across have a black as one of the colors in each pair; make it the negative, next color, no mattter what it is, will be the positive.:thumbup:


that whats i do, black is never positive on my dc wiring on field device. it is negative. White or red is positive depending on colors on cable.


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## Aydin2011

scameron81 said:


> You mean like this. Control wire is the same color and same size regardless of system or voltage. You really have to watch what you're doing and read the labels.


I try to carefully with color code. Specially main power if it is 480 v ac at least I can identified brown, orange, yellow till I step down to the voltage. Also current and wire size is important for me. Low voltage I use red and white 120 ac and dc blue (+)and black(-)


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## Wirenuting

KDC said:


> Honestly, anything that makes you refer to prints and think can't be all bad. I'd rather see things properly labeled and one colour than a rainbow and guess what's what.


Prints for us is as rare as the golden goose. 
I continue colors from cabinet to device and label all ends. If I'm fabricating a new controller, the colors will match the buildings other control panels color pattern. 
I also like to write notes for the next person on, in or near every device or opening I come across.


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## KennyW

glen1971 said:


> Colors mess people up.. Eliminate all wire colors, go with black and number each wire.. Shielded pairs and triads would be easy - Wire #1 is +.. 2 wire devices with x-link (or thhn) would be the same..
> When I do industrial buildings in conduit I don't even try to pull circuits by phase color any more for the AC.. Controls are all black wire (12 volt, 24 volt or 120 volt)... Belden are terminated as per the client preference, white or black positive.. If there is no spec, or if it is new and not spec'd - white is positive..
> 
> Just my 2 cents...


To be honest you have a point. The field wiring is not going to follow the panel color code anyways if you're pulling multiconductors.

Every customer seems to have a slightly different spec as well. 

What I find wild is how common using blue for 24vdc is. In my world blue means intrinsically safe and you wouldn't dare use blue wire on a non-IS circuit.


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## Big John

KennyW said:


> ...What I find wild is how common using blue for 24vdc is....


 It's specified as part of a US panel-building standard, that's the reason for that and red control conductors.


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## KennyW

Big John said:


> It's specified as part of a US panel-building standard, that's the reason for that and red control conductors.


Ah ok. Is intrinsically safe wiring identified by some other means?


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## Big John

KennyW said:


> Ah ok. Is intrinsically safe wiring identified by some other means?


 The code for it is that they are permitted to be light blue when there are no other colors of the same color. So if you had IS wiring in your control panel, you could still use a regular blue for your DC, or you could just label your IS wiring and use whatever colors you choose.


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## ponyboy

When I do conveyor control I use every color available to make my job easier. I'll just pick a color for a system and use it throughout. One color for starts, one for stops, one for e-stops, one for light curtains, photo eyes, bridge up/down, tension cable etc.... Seems a lot more practical than running a billion reds and hunting for number tags. Is that hack?


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## lefleuron

ponyboy said:


> When I do conveyor control I use every color available to make my job easier. I'll just pick a color for a system and use it throughout. One color for starts, one for stops, one for e-stops, one for light curtains, photo eyes, bridge up/down, tension cable etc.... Seems a lot more practical than running a billion reds and hunting for number tags. Is that hack?



Yes, thats hack. But beautiful.


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## sparky970

On one of my sites all field wiring for discrete 120v controls is brown. White is used if there is a neutral. On analog, black is positive.


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## ponyboy

lefleuron said:


> Yes, thats hack. But beautiful.


I'll take a picture when I get this current one terminated. It'll look like a bag of skittles


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## JRaef

The official standard for wiring in control panels, although not everyone follows it, is NFPA 79. Wire colors are described in chapter 14.2

Black = ungrounded line, load and control wires at the same potential as the main incoming supply. Could be AC or DC

Red = ungrounded AC control wiring at less than line voltage

Blue = ungrounded DC control voltage at less than line voltage

Yellow or orange = ungrounded circuits that remain energized when the main disconnect is open

White = grounded circuit conductor, could also be gray or another color if including 3 white stripes (other than green, blue, orange or yellow)

White with blue stripes = grounded DC control voltage

White with orange or yellow stripes = grounded circuit conductor that remains energized when the main is open

Green with / without yellow stripe = Equipment Grounding (Protective) Conductor.


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