The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!


2017 NEC and Related
2017 NEC
Now Available!

Recent Posts
Parking lot pole light swap....
by gfretwell
10/24/16 08:46 PM
International Wire Colour Codes
by Tjia1981
10/23/16 12:08 PM
Son of Sparky
by HotLine1
10/20/16 07:43 PM
Speaking of Plugmold ...
by gfretwell
10/17/16 02:37 PM
Broken battery charger? Check for cobwebs!
by gfretwell
10/17/16 02:30 PM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
gfretwell 14
ghost307 7
HotLine1 7
renosteinke 6
Potseal 4
Who's Online
0 registered (), 54 Guests and 5 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#134169 - 10/26/02 05:45 PM More color codes
CTwireman Offline

Registered: 02/07/02
Posts: 839
Loc: Connecticut, USA
Hi everyone. I thought I would throw out a few more color codes that we use here in the US.

As you may allready know, black, red, blue, brown, orange, yellow, and purple are all used as hot/live.

White or gray is always neutral, except when used for a switch loop in a cable assembly and is properly reidentified.

Green or bare copper is always ground/earth.

Our UK members may find this interesting. The black/red color code is used here...for DC systems. Red(+), Black(-). In fact, I just finished wiring my dad's boat and all boat cable I used is black/red. There is a new variety which is yellow/red, to cut down on the confusion with black=hot in AC.

Our fire alarm systems use these colors:
-black/red for interconnection between smoke detectors and pull stations.
-blue/white for interconnection between horns and strobe lights.

Audio cable (with one pair) for connecting speakers (for a home theater, for instance) is typically black/white or black/red. The other pair in a 2-pair cable is usually yellow/green.

Thermostat cable for central air conditioning sytems is red, white, green, blue, and yellow.

Confused yet?

If I think of any others, I'll post them.

[This message has been edited by CTwireman (edited 10-26-2002).]

Test Equipment:

Large Selection of Test Equipment For Electrical, HVAC, Test & Measurement
Large Selection of Test Equipment For Electrical, HVAC, Test & Measurement

#134170 - 10/27/02 07:16 AM Re: More color codes
j a harrison Offline

Registered: 05/22/02
Posts: 112
Loc: southampton, england
To CTwireman,
you think that your colour codes are complicated, well then mate try these.

Domestic supply cable,
lead locked, sheathed copper conductor, on either re, yellow, or blue phase (single 230v line in)then this goses to grey shethed 25mm meter tails (the connection from the PoCo meter and the clients mains distribution board,
these are red and black

Commercial is the same but the connections to the PoCo meter are usually three phase ( 3 x 230v ) these are again grey sheather 25mm copper, but they are connected to red,yellow and blue phases and are indentified by insukation tape.

then we get to switch return wiring, in domestic it is black with a red tape marker, the feeder is red.

In commercial it depends on the phase that is used, red for red (even in switch returns
unless it is two way switching and then it is red, yellow and blue) then you get permanant live supplies for emergency lighting fittings (flexable cable only) are red, blue, green/yellow,black,

Our fire alarms are easy, (sometimes) 4 core cable to detection/alarm sounders can be red.yellow,blue and black or two core red and black.

Burglar alarms are either 4 core, 6 core, 8 core, 12 core, 20 core, and if you really want a large joint box you can go for 40 core
red, yellow,blue,black,white,green,purple,turquise,grey,pink,violet,orange and some hace a white stripe to identify them.

Heating systems,
red,yellow,blue,black,brown,purple,and sometimes orange.
these are some of the colour codes we use from day to day,

we could go into the cctv side of things or the access control side as well but that gets a little more complicated as you did deeper.
But as a multitrade electrician, specification,drawing,supply and fit of all tubing, cable tray and the the wiring (first fix) then the wiring of all socket outlets,lighting fittings, also i do all the fire,security alarms, closed circuit television and computer controlled access control it gets a bit hectic sometimes.

I hope it helps you, if you want to know more
keep looking at ECN or e mail me, one

#134171 - 10/27/02 10:28 AM Re: More color codes
pauluk Offline

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
I think red & black for positive and negative of a 2-wire DC circuit is fairly universal, at least in the English-speaking world.

I once had a Russian radio in which the wires to the battery compartment were coded blue (positive) and pink (negative). Very strange!

Another system common here in the days of 3-wire DC circuits was:

red=positive outer
blue=negative outer

Official IEE Regs. specified that the negative outer should be white (or later, yellow), the same color as phase B on an AC system.

I've seen the new red & yellow marine cable in, I think, the Ancor catalog. They said it was introduced because of a few people who had accidentally cut into a hot black AC wire thinking it was 12V negative.

#134172 - 10/27/02 11:46 AM Re: More color codes
Texas_Ranger Offline

Registered: 12/17/01
Posts: 2332
Loc: Vienna, Austria
Red/black for DC is used here as well.

#134173 - 10/27/02 12:09 PM Re: More color codes
CTwireman Offline

Registered: 02/07/02
Posts: 839
Loc: Connecticut, USA
Well, as Paul mentioned in another thread, it appears that the British system is quite a mess.

Yes, Ancor brand is the cable I always use when doing marine wiring. The new red/yellow is called "Safety Wire." I have never used the red/yellow, and I probably never will. They sell it right along side the red/black at the boat stores, and the spools are usually gathering dust on the floor.

I concede the red/yellow is a good idea for larger vessels with 2 voltage systems, but anyone with any experience would know the difference. As I mentioned though, it hasn't really caught on. DIYers shouldnt be allowed to wire boats either, even though it's DC. It can still cause a fire.

BTW, how did you end up with an Ancor catalog? Do you do any boating yourself?

#134174 - 11/14/02 02:46 PM Re: More color codes
pauluk Offline

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
Sorry for the delay in replying. I'd lost track of this thread for a while!

I don't do any boating myself, but I have some friends who do, and the area in which I live (Norfolk Broads) is big with boat hire for tourists.

I think my Ancor catalog came through a British distributor with some other information I'd asked for -- Details on some inverters if I recall correctly, but it was a couple of years or more ago.

The cable ampacity tables in the front are handy.


ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals