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ckchew666
April 10th, 2006, 02:38 AM
Hi,

I don't have much experience in panel, appreciate it if someone can highlight me the standard color for a control panel with PLC control.

As I know:

240V AC - RED/BROWN
Neutral - BLUE
GND - GREEN

24V DC -
COM -

Digital signal Input -
Digital signal output -
Analog Input -
Analog output -
RTD -

etc.....

Is there a chart on this?? Thanks.

jolio ST
April 10th, 2006, 03:21 AM
Hi chew

It does depend on the customer's requirement for the colour coding. But a standard in my company goes like this:

24VDC+/- ->GREY
110VDC- ->BLACK
110+ ->RED
Single-phase AC Live ->RED
Single-Phase AC Neut ->BLACK
Three-Phase R ->RED
Three-Phase Y ->YELLOW
Three-Phase B ->BLUE
Three-Phase N ->BLACK
Ground/Earth ->GREEN/YELLOW
Analog IO, RTU cables uses shield cable, in either 2-wire, or 3 wire where:
3 Wire:
Positive -> Red
Negative -> Black
Neutral/Common -> White/Clear
2 Wire:
Positive ->White/Clear
Negative ->Black

But many companies have different preferences.
I also found a link to some old posts:
http://www.plctalk.net/qanda/search.php?searchid=233341

Hope it helps:beerchug:

regards
Sherine T.

ckchew666
April 10th, 2006, 04:06 AM
Hi chew

It does depend on the customer's requirement for the colour coding. But a standard in my company goes like this:

24VDC+/- ->GREY
110VDC- ->BLACK
110+ ->RED
Single-phase AC Live ->RED
Single-Phase AC Neut ->BLACK
Three-Phase R ->RED
Three-Phase Y ->YELLOW
Three-Phase B ->BLUE
Three-Phase N ->BLACK
Ground/Earth ->GREEN/YELLOW
Analog IO, RTU cables uses shield cable, in either 2-wire, or 3 wire where:
3 Wire:
Positive -> Red
Negative -> Black
Neutral/Common -> White/Clear
2 Wire:
Positive ->White/Clear
Negative ->Black

But many companies have different preferences.
I also found a link to some old posts:
http://www.plctalk.net/qanda/search.php?searchid=233341

Hope it helps:beerchug:

regards
Sherine T.

Sherine,

Thx for ur info, but we don't have an international standard or something like tat?

If the AC & DC using the same color coding, will it be dangerous when trouble shooting or during maintenance work?

Thanks.

nswu1
April 10th, 2006, 05:26 AM
It is a better practice to always use different colors for ac/dc voltages. As a rule of thumb I use red for ac,blue for dc, green for ground,white for neutral.

ckchew666
April 10th, 2006, 05:47 AM
It is a better practice to always use different colors for ac/dc voltages. As a rule of thumb I use red for ac,blue for dc, green for ground,white for neutral.

How about AC neutral and DC common? AC & DC must have total 4 different color code, right?

SimonGoldsworthy
April 10th, 2006, 07:42 AM
Have a look at IEC 204-1 (or the European version EN60204):

e.g.

Black=Power
Blue=DC control
Red=AC control

Tom Jenkins
April 10th, 2006, 09:03 AM
In the US the only regulated colors are:

White or Grey = Neutral or grounded current carrying conductor
Green or Green/Yellow stripe = ground
Any other color = current carrying conductor

In most industries the following "standard" is common for control:
Blue = DC
Red = 120 VAC control
Black = Power above 120 VAC, usually with separate color tapes like Red/Blue/Orange for each phase of a three phase power
Yellow = foreign voltage, that is a conductor which is powered by a source outside the panel itself

jtn
April 10th, 2006, 09:27 AM
If you are building UL listed panels in the US there are guidelines for the color of all the wires in the panel. We have had companies tell us that they want the panel built with their wiring color code and also want a UL label on the panel. We have had to come back and tell them that we have to use the UL 508 color code or we can't put the UL 508 sticker on the panel. When I was in the SE I never had to build UL panels so it didn't matter, but when I moved to the NW I began working in the water/wastewater field and all the municipalities required UL panels. Also the industrial panels in Washington that I build now require UL.

nswu1
April 10th, 2006, 09:53 AM
So what are the UL-508 color scheme?

jtn
April 10th, 2006, 10:51 AM
I don't work at a place that has a panel shop now, so I don't have the manual handy. I will stop off this afternoon on the way home and get a copy of it though (I've been meaning to do this for a while now) and post them tomorrow. Maybe today if I get the chance to run over there during lunch (if I get a lunch today!).

jolio ST
April 10th, 2006, 11:03 AM
That's is when labelling, grouping and allocation comes in. The designer who draws will usually put up AC components and wirings to a location and DC components and wirings to another location. Labelling enables the differentiation of AC single-phase from AC three-phase. for DC, cable size and good labelling will distinguish between low DC voltage from high DC voltage.

I've read about the IEC standards thingy, but it still boils down to clear details of where this perticular wire belongs to.

But whatever the situation is, I face a great problem whenever I start comissioning the project that left the factory. The control panels look great in the factory, all new and clean, and tested to work. When it is delivered to site, especially one I'm having a headache now, is on board a vessel due to Brazil. The panels are a MESS!! panels dented, meters cracked, relays demaged, keys missing, wires tampered with, and lock being forced opened. Worse still, the panels were certified IP 65, and some bleeding sub-contractors working on the field wirings just drilled 5 big holes on the base for their cables!:eek: There goes the certification.

RBergmann
April 10th, 2006, 05:57 PM
If you are building UL listed panels in the US there are guidelines for the color of all the wires in the panel. We have had companies tell us that they want the panel built with their wiring color code and also want a UL label on the panel. We have had to come back and tell them that we have to use the UL 508 color code or we can't put the UL 508 sticker on the panel. When I was in the SE I never had to build UL panels so it didn't matter, but when I moved to the NW I began working in the water/wastewater field and all the municipalities required UL panels. Also the industrial panels in Washington that I build now require UL.
We are a UL 508 shop and I've never heard of a UL 508 wire color coding standard.

Generally, we use NFPA 79 as our guide for machine tools which pretty much follows what Tom Jenkins said previously. The only extra color we have adopted is blue w/ white stripe for DC 0V.

rsdoran
April 10th, 2006, 06:35 PM
UL certification is based on NFPA/NEC code/standards. The new Article 409 in NEC 2005 is the primary authority...note: if you use the latest version of NFPA 79 you will be in accordance.

It should be noted that many do not consider NFPA/NEC an authority BUT it should be noted that OSHA (US government authority) requires compliance using NEC and NFPA 79 and a few other standards the NFPA has developed.

What does this mean? It means that you can build it any way you want BUT if someone does get hurt and OSHA investigates and the machinery does not meet or exceed specifications then the company will have problems and many people could be considered liable.

Certain industries may have exemptions to a point but usually it is because another authority requires more extraneous specifications.

You can never rule out OSHA, or the FDA, in the US. I have seen both close a plant....the FDA actually put chains around the building.

darrenj
April 10th, 2006, 11:28 PM
i use yellow for internal 24vdc wiring, blue for external wiring..red for 110 white for 110v Neutral, red black blue for 3 phase 208 volt and yellow black and brown for 600v

Didnt get this from a book just used standards that ihad seen before..

LadderLogic
April 10th, 2006, 11:44 PM
In the US the only regulated colors are:

White or Grey = Neutral or grounded current carrying conductor
Green or Green/Yellow stripe = ground
Any other color = current carrying conductor

In most industries the following "standard" is common for control:
Blue = DC
Red = 120 VAC control
Black = Power above 120 VAC, usually with separate color tapes like Red/Blue/Orange for each phase of a three phase power
Yellow = foreign voltage, that is a conductor which is powered by a source outside the panel itself

That is pretty much what we follow with only one modification(probably adopted after some European standards): brown for DC positive bus (usually +24 VDC)

GEOFRA
April 11th, 2006, 12:00 AM
See attached file for EU standards.
The only weak point I see is the use of blue color as AC neutral and DC 0V which is confusing.

jtn
April 11th, 2006, 09:04 AM
UL-508A Manual section 66.9 gives a color code for internal control wiring. It is as follows:

a) Black - all ungrounded control circuit conductors operating at the supply voltage.
b) Red - ungrounded ac control circuits operating at a voltage less than the supply voltage.
c) Blue - ungrounded dc control circuits.
d) Yellow - ungrounded control circuits or other wiring, such as for cabinet lighting, that remain energized when the main disconnect is in the "off" position.
e) White or natural gray - grounded ac current carrying control circuit conductor regardless of voltage.'
f) White with blue stripe - grounded dc current carrying control circuit conductor.
g) White with yellow stripe - grounded ac control circuit current carrying conductor that remains energized when the main disconnect switch is in the "off" position.

Exception: Leads on assembled components, multiconductor cable, leads used to connect electronic devices, and conductor sizes 20-30 AWG are not required to comply with this requirement.

Tark
April 11th, 2006, 11:18 AM
In the US the only regulated colors are:

White or Grey = Neutral or grounded current carrying conductor
Green or Green/Yellow stripe = ground
Any other color = current carrying conductor


Orange = High Leg

It's a popular test question.

RBergmann
April 11th, 2006, 11:54 AM
UL-508A Manual section 66.9 gives a color code for internal control wiring.
Thanks, JTN ...

I'm glad that I have someone else at my company that has to deal with this on a regular basis. When I searched the PDF of the 508A standard, I couldn't come up with the color requirements (obviously, wrong search terms) but your direction was all I needed to see the error of my assumptions.

... rab

jtn
April 11th, 2006, 12:01 PM
Thanks, JTN ...

I'm glad that I have someone else at my company that has to deal with this on a regular basis. When I searched the PDF of the 508A standard, I couldn't come up with the color requirements (obviously, wrong search terms) but your direction was all I needed to see the error of my assumptions.

... rab
It can be tough to find stuff in there if you don't read it regularly. Our shop supervisor was the 508A guru, I know enough to be able to spot discrepancies in the specs so I can call them out in submittals.

504bloke
April 11th, 2006, 12:35 PM
Along with EN60204

Black- ac and dc power circuits
Red - ac control circuits
Blue - dc control circuits
Orange - Interlocks fed from an external source.

504bloke
April 11th, 2006, 12:40 PM
See attached file for EU standards.
The only weak point I see is the use of blue color as AC neutral and DC 0V which is confusing.

I dont think thats for control panels its for Installation Cables.

The Blue you list is actually the internal core of say the twin and earth cable used to wire house lights and power outlets (13Amp sockets).

The old twin and earth was red and black, the new (to come into line with europe) is Brown and Blue.

The same goes for three phase conductors up a cable, these used to be Red,Yellow,Blue the new european colours for say a Steel Wire Armoured 3 core is Brown, Black & Grey

Kidblue
April 12th, 2006, 03:25 AM
I dont think thats for control panels its for Installation Cables.


Think you'll find it now affects panel wiring too!! (It was a surprise to me as well! ;) )

We changed over about 9 months ago......

GEOFRA
April 19th, 2006, 11:20 PM
504bloke the color coding is valid for panels too. Here in Cyprus everybody has adopted it including myself. As I told in my previous post the only confusing is the neutral which is blue and the same color is used for ELV. Here we are a little bit flexible and we may use some other color for 24V DC or AC. At least I can use the same color for these as I always connect 0V of both 24v sources (AC,DC)to earth.

tom_stalcup
April 20th, 2006, 01:42 AM
The panels we get from overseas(germany) come with +24 being blue.... And -24 being blue with a white stripe....

JohnW
April 20th, 2006, 07:47 AM
Think you'll find it now affects panel wiring too!! (It was a surprise to me as well! ;) )

We changed over about 9 months ago......

The IEE 16th edition specifically excludes electrical equipment (i.e control panels) so I would go along with 60204.

MikeW
April 20th, 2006, 07:54 AM
The panels we get from overseas(germany) come with +24 being blue.... And -24 being blue with a white stripe....
I believe that is the convention for grounded DC, ungrounded is red and black.

krk
April 20th, 2006, 08:04 AM
I'm with SimonG & JohnW on this one....

A control panel is an integral part of the machine as a whole and therefore falls under EN60204-1

Fixed wiring and associated distribution equipment such as switchboards, panelboards etc. should follow the new colour codes in BS7671:2001:Amendment No.2:2004 (in other words the latest 16th Ed.)

Of course, this is only IMHO.

vooduk
January 4th, 2010, 12:31 PM
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 in OFF position.

White with blue stripe- grounded DC current carring conductor.

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

silva.foxx
January 4th, 2010, 01:45 PM
Come on Vooduk... keep up... we're in 2010!

Welcome to the forum.

.

leitmotif
January 4th, 2010, 02:39 PM
Come on Vooduk... keep up... we're in 2010!

Welcome to the forum. .

Yeah but look at the brightside - he did a search like everyone advises and found the info.

Dan Bentler

brucechase
January 6th, 2010, 03:00 PM
Hello,

UL508a specified:

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



Are you sure about Yellow?

See this thread.
http://www.plctalk.net/qanda/showthread.php?t=49445

MikeW
January 7th, 2010, 08:23 AM
Trying to standardize on a "uniform" color code losses sight of a possible larger problem for those who can't distinguish colors very well, if at all. (Yes, I work with a top notch panel builder who has trouble with this, he can not wire a RJ45 connector without someone helping him figure which wire goes to what pin as the thin colored stripes are hard to tell on the white wires.)

Tag all wires with numbers that match the wiring diagram and color is unimportant.

OkiePC
January 7th, 2010, 08:58 AM
Tag all wires with numbers that match the wiring diagram and color is unimportant.

I agree that wiring should be labelled, but color is still very important. Certain colors have certain meanings to the 92% of us who are not colorblind, and those color standards should be followed.

I don't want to see a green wire used for anything but ground, or a black wire used for a 120vac neutral...etc.

Just my opinion,
Paul

kamenges
January 7th, 2010, 09:11 AM
Originally posted by OkiePC:

I don't want to see ... or a black wire used for a 120vac neutral...etc.

...unless you happen to be in Australia.

Keith

bernie_carlton
January 7th, 2010, 09:23 AM
Are you sure about Yellow?

NFPA79 - 2002 this was Orange OR Yellow

NFPA79 - 2007 this was only Orange

mdprice55
April 6th, 2010, 02:19 PM
There is no standard UL color code other than for grounding conductors.

silva.foxx
April 6th, 2010, 02:46 PM
:bawling:

TConnolly
April 6th, 2010, 03:12 PM
Welcome to the forum mdprice55. We certainly hope to see more of you around.

UL standards do carry considerable clout, not just in the US but worldwide. It behooves us all to follow UL standards. Underwriters Laboratories is not a regulatory authority. It is a private, for profit, testing corporation which licenses companies to carry the UL label which certifies that the product meets certain standards.

In the USA electrical codes are regulated for the most part by NFPA 70 (The NEC), and with regard to control panels - the subject of this thread - NFPA 79. Local jurisdictions (AHJ) have the final say but it is very rare that an AHJ doesn't follow NFPA 70 and/or NFPA 79. NFPA 79 is the standard for electrical machinery and it specifies a few color codes and explicitly reserves some colors for specific applications. The colors are spelled out in NFPA 79 13.2. Even though UL might not spell out something, it would be difficult to obtain a UL marking if a manufacturer cannot demonstrate that his product meets regulatory standards or standards mandated by the AHJ. In this case UL follows NFPA 79.

This is an old thread which has been resurrected and the subject has been discussed in many different threads since this one originated. I'll simply reiterate that its probably a good idea for anyone building control panels to get the current copy of NFPA 79 and become familiar with it. Some things have recently changed, such as the change in YELLOW/ORANGE mentioned earlier.

The Plc Kid
April 6th, 2010, 05:18 PM
What about 24 volts Ac? Would it still be red?

TConnolly
April 6th, 2010, 06:33 PM
Yep.
NFPA 79 13.2.4.3(2) There are however four exceptions that are pretty broad.

daba
April 6th, 2010, 07:16 PM
Judging by the diversity, and contradictory, discussions on this topic, the only SAFE way to approach a panel's innards is with the knowledge that the panel-builder MIGHT have followed a published and accepted colour scheme, but it is safer to assume he didn't, unless there is a conformitory declaration attached to the panel.

I have NEVER seen a panel that has any documentory evidence that states what standards the panel is wired to.....

best not to assume anything

Mike Lamond
April 7th, 2010, 12:29 PM
Judging by the diversity, and contradictory, discussions on this topic, the only SAFE way to approach a panel's innards is with the knowledge that the panel-builder MIGHT have followed a published and accepted colour scheme, but it is safer to assume he didn't, unless there is a conformitory declaration attached to the panel.

I have NEVER seen a panel that has any documentory evidence that states what standards the panel is wired to.....

best not to assume anything

At my first job, our standard practice was to put notes on the first sheet of each panel's electrical schematic, including such details as conductor size and color, terminal symbols and other useful information. I still do that. Of course there's no guarantee that the same colors were used for field wiring or wiring changes by others or that there are still drawings in the panel 15 years later...

Note to beginning engineers: Do not try to coordinate control panel wire colors with building power distribution. There is no need to use #12 AWG pink instead of black for the small DC drive outputs to the chemical pump motors. :)

robsimpson
June 29th, 2010, 04:26 PM
Question from Canada. I'm getting a panel from a US vendor for a gas plant I'm working on. We have a project spec for panel colors. The vendor says he MUST follow UL505A for the colors. There will be likely 15 other PLC packages on site, I don't want 14 the same and this one different.

Is UL508A mandatory or recommended for control panel wire colors? Also the panel must be either cUL or CSA, I don't actually care if it is UL508A or not. I think the vendor is just accustomed to meeting UL508A. If the vendor is planning on providing cUL would that mean that he then needs to meet UL508A?

Thanks in advance.

OZEE
June 29th, 2010, 09:10 PM
UL508A does not specify wire colors.

Paul B
June 30th, 2010, 09:31 PM
Glad to see this old thread resurrected.

Been doing this 20 years (I'm just a newbie!!!) and we use:

Black - 230-575 3-phase
Red - 120vac hot
White - 120vac neutral
Blue - 24vdc hot
White with blue stripe - 0vdc
Green with yellow stripe - ground
Yellow - foreign voltage, hot with panel disconnect off. This should be orange based on previous post.

Orange - DC drive motor wire positive
Brown - DC drive motor wire negative

The DC drive motor wires don't come up too much in the past five-ten years.

504bloke
January 6th, 2011, 01:55 PM
Judging by the diversity, and contradictory, discussions on this topic, the only SAFE way to approach a panel's innards is with the knowledge that the panel-builder MIGHT have followed a published and accepted colour scheme, but it is safer to assume he didn't, unless there is a conformitory declaration attached to the panel.

I have NEVER seen a panel that has any documentory evidence that states what standards the panel is wired to.....

best not to assume anything

I have, lots, mostly EN 60204-1, with the colours labelled on the first page of the drawings

daba
January 6th, 2011, 06:00 PM
I have, lots, mostly EN 60204-1, with the colours labelled on the first page of the drawings

A double post resurrection ! wow !

Anyway - your panels have drawings in them ? You're spoilt !

Yes, I know it's "Good Practice", sometimes "Company Standard", and sometimes "Obligatory", that panel drawings are actually In The Panel (add that to your wish-list !).

If I could gain access to all the panels I have worked on in the last 30 years, I could guarantee that at least 30% of them would not have their schematics in the provided holder inside the door.

And in any plant, standards change, sometimes the company just wants to align themselves with "national standards", sometimes they just do a re-think about it, and only the latest panels conform to the latest specs.

So I still stand by my statement

.... the only SAFE way to approach a panel's innards is with the knowledge that the panel-builder MIGHT have followed a published and accepted colour scheme, but it is safer to assume he didn't, unless there is a conformitory declaration attached to the panel.

PS Not sure that's a real word "conformitory" - English was never a strong language for me, lol

RBergmann
January 7th, 2011, 05:19 PM
Yes, I know it's "Good Practice", sometimes "Company Standard", and sometimes "Obligatory", that panel drawings are actually In The Panel (add that to your wish-list !).
As the past owner of a UL508A panel shop, we always provided schematics in a pocket inside the listed panels (as required by UL).

Funny thing though ... when I would go to a job site for trouble shooting, the schematics were often missing. Management or supervision would remove these documents for a reason that I could never understand or get a reasonable answer to.

Since this post is regarding wire colors, these days NFPA70 (NEC), NFPA79 and UL 508A have established color guidelines in the US. Before then, JIC (Joint Industry Council out of McClain, VA ... late 70's) had documentation that is remarkably similar to NFPA79 that also provided similar guidelines.

So for my company, we never had a question as to standardization of these colors.

seppoalanen
January 8th, 2011, 01:19 PM
As we can see, there are a lot of colours and needs in the world.
So, in my CAD have selection for the Colors in the Project Data Base.
In the Circuit Diagrams, Wiring lines have properties as 24VDC control wire, analog signal wire etc, not the Color propery! Wire Colour comes via Project Data Base. Drawings are usable from project to project, only Project Data Base have to change if necessory.

There are more examples on my home pages http://www.alanen.info (http://www.alanen.info/)

504bloke
January 8th, 2011, 02:58 PM
A double post resurrection ! wow !

Anyway - your panels have drawings in them ? You're spoilt !

Yes, I know it's "Good Practice", sometimes "Company Standard", and sometimes "Obligatory", that panel drawings are actually In The Panel (add that to your wish-list !).

If I could gain access to all the panels I have worked on in the last 30 years, I could guarantee that at least 30% of them would not have their schematics in the provided holder inside the door.

And in any plant, standards change, sometimes the company just wants to align themselves with "national standards", sometimes they just do a re-think about it, and only the latest panels conform to the latest specs.

So I still stand by my statement



PS Not sure that's a real word "conformitory" - English was never a strong language for me, lol

Sorry - My Bad

Didnt actually mean that, i meant referring to your post that the colours of the standard were on the drawings ie 60204

I'd agree mostly with that figure, most of my customers are now trained though as it costs thme lots more if they have no drawings, obviously all my panels i have the dxf files anyways