Red wire or black?

Should all wiring under line voltage be red or only (ac)control wiring be red? I always used red for ac control. We have an inspector that is saying anything under line should be red. This included power wiring to drives that are under line.

As far as I know, there's no code for that, but I'm "just the programmer". The only coded-colors that I'm aware of are white and green.

i don't know ıf there is a standart or not but i usually saw that +24vdc cables are blue, 1ph line voltage(220 V ac) cables are red and 3ph line volatge (380 V ac) cables are black.

NEC and UL 508 are silent on the subject, except for Green = Ground, white or grey = neutral.

Convention in many places is:

Line above 120 AC powerblack
Line 120 AC power or control = red
White = Neutral
Green = Ground
Blue = DC (24 VDC typical)
Yellow = foriegn vlotage (a circuit that is powered from outside your panel and may remain live with unknown voltage if your panel is off.)

What standard is the inspector referencing?

I have been designing panels for over 20 years and I always used Black for line wiring, Red for control and below line voltage(230) and Blue for 24 Vdc, Green or green/yellow for ground. Yellow for power coming from different source.

Coulor

In the Canadian Code it is under section #4.

bill4261 said:

Should all wiring under line voltage be red or only (ac)control wiring be red? I always used red for ac control. We have an inspector that is saying anything under line should be red. This included power wiring to drives that are under line.

Click to expand...

depends on statury requirement of the country. However for control grey colour and power red, yellow and blue accoring to the phase

UL 508 prefers (but does not require) that:
line voltage = black
ungrounded AC control circuits at less than line voltage = red
ungrounded DC control circuits = blue

These are the same recommendations made in NFPA79.

Unless it has changed

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.

NFPA 79 can be viewed here but it should basically be the same: http://www.nfpa.org/freecodes/free_access_agreement.asp?id=7907

When the book opens there will be a LIST icon at the bottom, if you click this a Table of Contents will show and you can go directly to Chapter 13 which shows wire colors. I suggest reading all of it but 9-13 may offer the most help.

Ron, you are correct about UL-508 - my mistake!

Tom

UL-508A 66.9 does not apply to all UL-508A listed equipment.
But, when you know that there is an accepted industry standard, why would you want to do things different?

Tom Jenkins said:

NEC and UL 508 are silent on the subject, except for Green = Ground, white or grey = neutral.

Convention in many places is:

Line above 120 AC powerblack
Line 120 AC power or control = red
White = Neutral
Green = Ground
Blue = DC (24 VDC typical)
Yellow = foriegn vlotage (a circuit that is powered from outside your panel and may remain live with unknown voltage if your panel is off.)

What standard is the inspector referencing?

Click to expand...

In this system, if the power is 3-phase 208VAC without neutral, should it be colored red or black?

Personally never seen a 208vac system without a neutral, its a wye transformation from a delta supply.



The gist of the codes, standards, or any guide is to separate the SUPPLY from the control voltage. The guides these days conform to the idea control voltage will always be less than 150vac, and leaning even more toward less than 50vdc.

The supply, which should always be greater than 150vac for most industrial or commercial applications, will always be black. What is that voltage? Should be designated and tested upon entry to the panel involved.

Regardless of the colors used, ALWAYS TEST IT, preferably not with your tongue.

Could you still answer my question, pls?
Not whether it is a rare or common case?
Neutral is not supplied into the enclosure. Of course, it exists somewhere on external transformer.

The color part I did answer the question, it will be black, it is an ungrounded AC supply conductor above 150vac.