US Wiring Colour Code

[anjou]

Ive got a Newmar AC/DC panel and the primary wires are all black and white for both AC and DC

Am I right in thinking that in the US, white is negative/neutral and black is live/possitive?

[btrayfors]

In single-phase AC circuits in the U.S., white is neutral, black is hot, and green is earth ground.

Sometimes these are called "grounded", "ungrounded", and "grounding", respectively, just to confuse things :-)

In DC circuits in the U.S., the positive wire is red and the negative wire is black or yellow. The yellow color was adopted recently in order to avoid confusion between the DC black which is ground or negative, and the AC black which is hot.

I'm surprised that NewMar would not follow this code. Be careful not to confuse AC and DC.

Bill

[dandrews]

Originally Posted by anjou

Ive got a Newmar AC/DC panel and the primary wires are all black and white for both AC and DC

Am I right in thinking that in the US, white is negative/neutral and black is live/possitive?

That is correct for AC circuits. For DC circuits, the current code is red and yellow. Yellow being negative or the return.

Don

[anjou]

Thanks guys, my memory is shot, im now looking at the panel and you are right

The DC side is red and black, the red is obviously the live

The AC side is black and white, so based on what you have said, the black is hot and the white is not ....ie, on this older panel, the white is neutral or negative

Thanks

[btrayfors]

Originally Posted by anjou

Thanks guys, my memory is shot, im now looking at the panel and you are right

The DC side is red and black, the red is obviously the live

The AC side is black and white, so based on what you have said, the black is hot and the white is not ....ie, on this older panel, the white is neutral or negative

Thanks

Correct, except that there is no "negative" in AC circuits....because in alternating current (AC) circuits, current doesn't flow in a single direction, as it does in DC circuits. Rather, it alternates in direction at 50 or 60 times a second. The black is called Hot or Ungrounded. The white is called Neutral or Grounded. And the green is called Grounding.

Normally, the neutral (white) is connected to the grounding (green) only at the source.....shore, generator, or inverter.

Bill

[Tellie]

Which model panel do you have? Also what wires are you calling the primary wires? I find it odd that white was used as a primary to the panel for DC. Are you thinking the circuit wires? Newmar panels usually have a pretty good diagram for their panels showing proper wiring. But then most panel manufacturers assume qaulified electricians are working on them and that they should know the identifying color codes. These are the types of things you find when someone who doesn't have much experiance in electrical work deciding to be their own electricians. At the least I'd follow each DC white wire to it's source and tape back each end at least 10" with the proper colored tape, red, black etc. It's not the best solution, re-wiring would be the best, but at the least it will help anyone else working on the system in the future to know something is amiss.

[Tellie]

Originally Posted by anjou

Thanks guys, my memory is shot, im now looking at the panel and you are right

The DC side is red and black, the red is obviously the live

The AC side is black and white, so based on what you have said, the black is hot and the white is not ....ie, on this older panel, the white is neutral or negative

Thanks

Good, that makes me feel a bit better. But if you need a diagram for Newmar panels this might help... Newmar Product Manuals

[mbianka]

Originally Posted by anjou

Thanks guys, my memory is shot, im now looking at the panel and you are right

The DC side is red and black, the red is obviously the live

The AC side is black and white, so based on what you have said, the black is hot and the white is not ....ie, on this older panel, the white is neutral or negative

Thanks

Anjou:

A good way to remember about the US AC wiring code is that when something gets "hot" and burns up it turns black. Therefore in AC circuits the hot is the black wire.

[anjou]

Thanks again guys

It was only the question of black and white i was unsure of because of the black being neg/neutral in the 12vDC side and then its used as the live in the AC side.

Its an old panel thats been used before and now im just using it for the breakers, so a few things have moved about and the original diagram may not be relevent anymore

[Wotname]

Anjou, for the record, what is the convention in the UK re AC & DC??

[anjou]

For 240v AC, domestic wiring, its green/yellow earth, blue/black neutral and red/brown live
The reason there is a choice is because the EU changed the colour a few times to make sure electricians are paying attention
415v AC 3 phase is different and I cant remember which 4 wire colours are used


With lower voltage DC its usual that red is live and black or blue is neutral and green/yellow is earth, but im not sure there is a hard and fast rule on this.

[Tellie]

Juuuuust to carify, there is no neutral in DC. A simple terminology slip that can add a little confusion when discussing AC and DC.

[David M]

DC, positive-negative

AC, hot-neutral-ground

It is too bad the color black is not consistent between the two. This is where there is a lot of confusion.

[Marner]

The ABYC (American Boat and Yacht Council) standards specify white as negative and black for positive for boat DC wiring.

Why they elected to use such colours is a mystery. Nearly all DC equipment comes with red (positive) black (negative) wiring. So the red equipment wire has to go to the black and the black equipment wire to the white.

All the wire I used when building our boat was black and white, but to avoid any confusion I wired it white positive and black negative.

Marner
___________________________
http://cruising-cape-breton.info

[btrayfors]

Originally Posted by Marner

The ABYC (American Boat and Yacht Council) standards specify white as negative and black for positive for boat DC wiring.

Why they elected to use such colours is a mystery. Nearly all DC equipment comes with red (positive) black (negative) wiring. So the red equipment wire has to go to the black and the black equipment wire to the white.

All the wire I used when building our boat was black and white, but to avoid any confusion I wired it white positive and black negative.

Marner
___________________________
http://cruising-cape-breton.info

No, Marner, that's not so.

ABYC specifies on p58 of E11:

TABLE XIV - WIRING COLOR CODE

Color Use
Green, or green w/yellow stripe(s) -- DC grounding conductors
Black, or yellow -- DC negative conductors
Red -- DC positive conductors

Bill