DC Wire Colors

The Plc Kid · Sep 1, 2009

When wireing 24 vdc control circuits i know that it supposed to be blue and blue/white stipe but i see some machines that have blue and white/blue stripe.

My question is which is correct or are both? If both which is best?

What is the typical application or use of the other color?

Sinc_green · Sep 1, 2009

Can't be sure I speak for everyone, but for us blue with a white stripe is the lower potential on an ungrounded circuit (ie +/-12V) while white wire is grounded neutral, the blue stripe indicating that it is used in 24VDC control.

The Plc Kid · Sep 1, 2009

Right

The choices are

Blue with a white Stripe

White with a Blue Stripe

But which is correct for the u.s.?

TConnolly · Sep 1, 2009

NFPA 13.2.3.2

The use of other colors for the following applications shall be as follows:
(1) WHITE with BLUE stripe for grounded (current-carrying) dc circuit conductors.

Exception No. 2. Where the identification of machine power and control wiring is such that compliance with the mandatory color codes is too restrictive for specific applications, it shall be permitted to use additional identification at selected locations as an alternative. This means of identification shall be permitted to be by separate color coding, marking tape, tagging, or other approved means and shall be permanently posted on the inside of the main electrical control panel enclosure in a visible location.

--------------------------------------------------------

Note that this says grounded current carrying conductors. If you don't ground your DC power supply 0V then it might not apply.

Of course, if you are buying wire from automationdirect, then you might have to settle for blue with a white stripe instead. Just claim its white wire with a really big fat blue stripe.

In a pinch I've stripped my own using white MTW and a blue permanent marker. A marker with a big flat tip works well. Put on a rubber glove and hold the wire against the marker tip with one hand while pulling it through with the other hand. You can quickly stripe a couple of dozen feet. Works in a pinch if you run out or need just a few feet. I wouldn't do it for a big job though.

Sinc_green · Sep 1, 2009

*response removed*

Kent Hostetler · Sep 11, 2009

Does anyone know where to get White w/blue stripe and white w/orange stripe colored wire?

dahnuguy · Sep 11, 2009

Germans use blue blau and brown , brauwn, with umlots. USAF uses black for all DC common and red for DC positive. GM and Ford use black and red.

The above regulation says you can use any label you like as long as you declare it.

"Exception No. 2. Where the identification of machine power and control wiring is such that compliance with the mandatory color codes is too restrictive for specific applications, it shall be permitted to use additional identification at selected locations as an alternative. This means of identification shall be permitted to be by separate color coding, marking tape, tagging, or other approved means and shall be permanently posted on the inside of the main electrical control panel enclosure in a visible location."

Translation, use what works for you and post a note in the cabinet.

Of all the companies I have worked for and with, I have not seen any standard used consistantly except for the Germans. They are consistant.

The American companies I worked with, use the wire they have on the shelf or what the supplier has in stock the day they order.

Once the spec called for colored wire to be used inside the cabinet. We looked in the cabinet. It was wired in all black MTW for everything. The panel builder said " This is North Carolina, that IS colored wire."

We hooked it up and put it in production and no one mentioned wire color again.

TConnolly · Sep 11, 2009

Kent Hostetler said:
Does anyone know where to get White w/blue stripe and white w/orange stripe colored wire?

Any electrical distributor worth their salt can get it, they may not stock it, but they should be able to get it. We usually order the striped wire in 2500 ft rolls, usually a couple of rolls a time. It lasts a while.

Automation direct has blue wire with a white stripe if you want to use that as an option. Newark will stripe most of their wire if you request it, but Newark wire is usually a lot more expensive than your local wire house will be.

Rich1955 · Sep 11, 2009

dahnuguy said:
Once the spec called for colored wire to be used inside the cabinet. We looked in the cabinet. It was wired in all black MTW for everything. The panel builder said " This is North Carolina, that IS colored wire."quote]

Is black a color?

No, black is not a color; a black object absorbs all the colors of the visible spectrum and reflects none of them to the eyes.

ELake20 · Sep 11, 2009

On the Euro stuff we use brn + blu -

Internal stuff here at the shop its blu + blu/wht -

twisty · Sep 11, 2009

Rich1955 said:
dahnuguy said:

Once the spec called for colored wire to be used inside the cabinet. We looked in the cabinet. It was wired in all black MTW for everything. The panel builder said " This is North Carolina, that IS colored wire."quote]

Is black a color?

No, black is not a color; a black object absorbs all the colors of the visible spectrum and reflects none of them to the eyes.

Click to expand...

in visible light, black is the absence of color. in pigments, it is the addition of all colors. regardless, this is just a cheeky answer to your cheeky retort. =D

for the record, our UL508 shop does all 12 and 24vdc with blue and brown wire. usually it is specced out that way by the designing engineers.

jstolaruk · Sep 12, 2009

dahnuguy said:
......GM and Ford use black and red.......

In the automotive world, Red is 110vac and Black is any other current carrier over 50v, typically 480vac. Blue and blue/wht or wht/blue is 24vdc. Stripes are added to any color wire for specific use and can deviate depending on the facility.

The Plc Kid · Sep 13, 2009

What is white with orange stripe used for?

Kent Hostetler · Sep 13, 2009

Per NFPA 79

It goes with the ORANGE color of ungrounded ac circuit conductors which remain energized...

(2) WHITE with ORANGE stripe for grounded (currentcarrying)
ac circuit conductor, which remains energized
when the main supply circuit disconnecting means is in

the off position.

nic00 · Sep 13, 2009

If i remember correctly the OSG (UK) lists a number of colours you can use for DC + and blue for DC-... Don't have the book handy otherwise i would state the recommendation

DC Wire Colors

The Plc Kid

Member

Sinc_green

Member

The Plc Kid

Member

TConnolly

Lifetime Supporting Member

Sinc_green

Member

Kent Hostetler

Member

dahnuguy

Member

TConnolly

Lifetime Supporting Member

Rich1955

Member

ELake20

Lifetime Supporting Member

twisty

Member

jstolaruk

Lifetime Supporting Member

The Plc Kid

Member

Kent Hostetler

Member

nic00

Member

Similar Topics