400vac/24vdc Wire Colours

[Lancie1]

Tom,

I remember the standard to which you are referring. About 30 years ago, there were NEMA and JIC standards that required RED lights for Motor Running (danger) and Green for Motor Off (safe). Now those have been deleted, best I can find out. I suppose NEMA got tired of fighting the Bubbas that thought it should be the same as traffic lights (with them in the drivers seat, not as pedestrians where of course it is opposite)!

There are still a bunch of old Motor Control Centers out there that have those big RED pilot lights that go on every time a motor starts!

Interesting thought: Could it be that at one time everyone in the US thought like pedestrians, because most people did more walking than driving? Now I suppose we all think like drivers, even in New York City.

 

[Christoff84]

Lately as we've been updating old equipment with safety relays (mostly conveyor lines) I've been placing remote boxes that show the safety circuit has been disengaged with a green pilot light. I chose green because generally it means safe or go. Basically trained the operators that if the green light is on it is safe to enter, if the green light is off or wont come on, call the maintenance staff.

When I worked at AB assembling their MV MCC's we would see designs come down both ways, sometimes the red pilot light was for motor running, sometimes it was for motor stopped. Usually depended on where in the world it was being shipped.

 

[Lancie1]

I chose green because generally it means safe or go.

It all depends on your viewpoint (the point you are standing when you do the viewing of the light). If you are walking across the street and see a green light, you had better not ASSUME it means "GO". Your best plan is to wait for the RED light and the WALK sign. Then you can "go".

 

[chud]

Some post suggested wiring according to context not voltage.Hope i never encounter 1 of those. Would hate to be working in a panel where you switch off a 24v dc supply and find the hardway that there is 220v on the same colour coding. There is no law only guidlines. Panel builders should just use common sense. A different color for each phase,voltage,in and outputs

 

[Outrage]

Hi Brian, the colours you've quoted are generally what we have here on 'most' of our plant including the additional one mentioned by another member: ORANGE - Control Sourced from another panel.

In times gone by when I used to do design rather than maintenance these were the colours I generally used when I had a choise. Many industries and companies have their own standards that we had to work for when designing control systems such as Britich Steel(Corus)who i seemed to remember, used pink for instrument/clean earth, not sure if this is the norm over the usual green/yellow.

Cheers,

Lee

 

[tragically1969]

Personally speaking i dont think you need any 'opinions', what's stated in BS EN 60204-1 should be the only reference you should ever need.

 

[krk]

I posted some relevant extracts from EN60204-1 regarding wiring colour codes a few months back, they're here if your're interested..

http://www.plctalk.net/qanda/showpost.php?p=205249&postcount=9

 

[KP_EENG]

I have no idea what the standard is in the UK, expect IEC would be the norm. IEC and NFPA state blue for +dc and blue/white stripe for - dc.

In the past I got use to 24vdc being brown + and blue - but things have changed.

Actually, the 2002 NFPA 79 section 14.2.3.2 states that White with a Blue Stripe shall be used for the grounded current-carrying conductor.

14.2.4.3 states that ungrounded DC control conductor shall be blue.

I don't know about the IEC because I don't have a copy of the standard, but if you are going to sell equipment internationally then you should probably use the IEC standard because it will be accepted in the US as well as Europe and Asia.

Regards

 

[NBJamie99]

Anyone have an update on the color code since the late 2008 or early 2009 revision? Thanks.

 

[TheStarr]

My "norm" for chassis wiring...

+24 vDC = Blue
0 vDC = Blue with white stripe
AC Hot = Black
AC Neutral = White
AC from another cabinet (or not killed by panel disconnect) = Yellow
- Sometimes this is needed on servo drives so they won't lose thier home position.
Ground (AC or DC) = Green or bare
Shield ground = Green with yellow stripe

Seems to make sense to me. (Industry - Tier 1 Automotive Automation)

 

[NBJamie99]

That has also been my standard, but I am working on a project for the UK, in which they have just specified wiring to EN60204. I was also told that it has been updated since the version we have on file, and have not been able to locate any new info.

I was told that:

415: Brown, Grey, Black (L1, L2, L3)
110: ????
24VDC: Dark Blue (+), Light Blue (-)

But have not been able to confirm nor deny it, as well as determine the 110.

As everyone has said it seems to have a lot of loop holes for OEM being able to choose what they prefer, as long as it is consistent, and properly labeled. But I figure if it is part of a standard it should be one way, and only one way.

Thanks for the quick reply.

 

[504bloke]

Anyone have an update on the color code since the late 2008 or early 2009 revision? Thanks.

Take a look at Post 9 here

Yes i know its 2006 but if you PM Kevin he may well have the latest copy as he's a very decent chap.

 

[Hilgard]

Hi

Our company standard is as follows:

24 vDC-Red
0 vDC-Black

110 vAC(Live)-Pink
0 vAC(Neutral)-Grey

220 vAC(Live)-Brown
0 vAC(Neutral)-Blue

Earht- Green and Yellow

We don't use high voltage Dc Currents.


Regards

 

[NBJamie99]

Take a look at Post 9 here

Yes i know its 2006 but if you PM Kevin he may well have the latest copy as he's a very decent chap.

Done, thanks for the idea.

 

[vooduk]

Wire Color

Hello,

UL508a specified:

Black -all ungrounded power circuit conductor regardless of voltage.
White or Gray- or three white stripes grounded AC current carring conductor regardless of voltage.

Red- ungrounded ac control circuits at the voltage less than the supply voltage.

Blue-ungrounded DC control circuits.

Yellow or Orange- ugrounded control circuits that remains energized with disconnect OFF.

White with blue stripe- grounded DC current carring conductor.

White with yellow stripe- grounded AC control circuit conductor that remains energized with disconnect OFF position .