Control Panel Wire Colors

[thurman]

I'm looking for information on wire color codes for control panels. Normally I use wire colors as an "additional" identifier for functions.

Are there any rules (codes) which apply to using various wire colors in a panel. Normally DC in the US is Blue with White/blue stripe, Europe is Brown and Blue if I'm not mistaken.

I believe the color coding scheme has to be posted inside the control panel and listed in the machine documentation.

I perfer to use different colors for the 3 dc power supplies, 24 VAC, along with differnt color wires for Digital Inputs and Outputs on the controller.

In my situation I will have 480 3ph (black wires)
coming into a panel through a disconnect. From the disconnect I will have two transformers. One is 480 to 120 vac (Red/White)the other is 480 to 24 vac (Wire Color ?).

The 120 vac from the first transformer is going to a UPS (output Yellow or Orange ungrounded with grounded White/Yellow or Orange stripe) that will supply power to the DC power supplies for all controls in the panel. One 24 vdc power supply powers the internal controller along with SSRs, Hi Limit Controls etc. The second 24 vdc power supply powers all noisy devices, ie. relays or any inductive device. The third dc power supply (12 vdc) is for sensor power (pressure sensor, leak detectors etc).

The 24 vac from the second transformer will power low voltage station lighting.

Any help would be appreciated.

 

[jlhmaint]

everything i have seen or worked with in usa 120vac was red and everything 24vdc was blue. and 3phase 480 all 3 were black coming in. grounds green and green with yellow strips.

 

[jbartos]

Suggestion: Visit for example:

http://www.nema.org/index_nema.cfm/1427/

and download
WD 1-1999 (6 pages), Status: Active
General Color Requirements for Wiring Devices:
Contains color references for AC switches, plugs and cord connectors, receptacles, and other related wiring devices.

 

[busbar]

jlh's posting is consisitent with NEMA ICS1-2000 §7.6 for internal control-panel wiring.

 

[thurman]

Thanks for the pointers I have been going through the sites looking up info.

 

[jbartos]

Suggestion: Visit

http://www.continuouswave.com/whaler/reference/wireColorCode.html

etc. for another wire color code.

 

[djs]

Hello;
UL also has a standard, UL 508B

 

[HallJM]

Thurman,
There are some standards in addtions to UL 508B

NFPA 79-Electrical Standard for Industrial Machinery. (US)

EN 60204 - Safety of Machinery-Electrical Equipment of Machines Part 1:General Requirements (European)

These standards cover the design aspects and requirements building control panels and industrial equipment. This also covers the standards for wire colors.

 

[jbartos]

Suggestion: The control panel may interface external circuitry that has conductor colors governed by electrical code(s). This needs to be followed for safety reasons, e.g. ground conductor may be required to have green color.

 

[thurman]

Thanks for all the good tips. I have obtained the NFPA 79 which will be should be of help. In my case I typically have anywhere from 2 to 4 dc power supplies and 2 to 4 different AC voltages in one panel. All derived from a single 480 vac 3ph main coming through a disconnect and transformers/power supplies break the rest down.

In the past I have always found it benificial to have the different voltages differientated by color for ease of trouble shooting. (besides it sure looks pretty too)<grin>

I was hoping to make this fit the &quot;standards&quot; or perhaps that's make the &quot;standards&quot; fit what I wanted.

Thanks again. Every body has been helpfull. The links were all interesting also.

thurman