So easy to do this right, but they didn’t

[Wotname]

Way better to stick with the aviation standard - all wires are white

[FlyingScot]

Originally Posted by pesarsten

Wow, I'm really confused! I always thought that in the USA on 120 volt ac circuits. WHITE IS ALWAYS THE GROUNDED POWER CONDUCTER ( NUETRAL )

Someone else please chime in to clarify.

ABYC agrees with you.

[Tellie]

I'm of the 10% color blind, red and green deficient. I was a commercial electrician for 25 years. Guess I have some work I gotta go back and check on. Being color blind does not mean you cannot determine what is green and red.

[Sailmonkey]

Originally Posted by pesarsten

Wow, I'm really confused! I always thought that in the USA on 120 volt ac circuits. WHITE IS ALWAYS THE GROUNDED POWER CONDUCTER ( NUETRAL )



Someone else please chime in to clarify.

Yes, black is hot
White is neutral. The confusing post is wrong.

[transmitterdan]

No qualified electrician should ever be in danger due to colors of wires. A good electrician knows how to verify which wires are hot and which are not safely. Color coding is a convenience but a well trained and safety conscious electrician will pay zero attention to wire color.

As to amateur electricians, well that's a different thing altogether.

[cyan]

Originally Posted by Sailmonkey

Yes, black is hot
White is neutral. The confusing post is wrong.

+1
If AC, remember, don’t touch the poop.
USA=black
UK=brown

[hellosailor]

"Wow, I'm really confused! I always thought that in the USA on 120 volt ac circuits. WHITE IS ALWAYS THE GROUNDED POWER CONDUCTER ( NUETRAL )"
Nope. Dangerous assumption to make, even if that is often how the wiring was done. Depending on where you are in the US, household wiring may be 2-wire in a plastic jacket ("Romex") with no ground wires run and plastic junction boxes. Or, in the cities which have had extensive experience with massive fires (did you know Manhattan alone burned 1/3 and 1/4 of the way to the ground? And that's ignoring the Chicago Fire and the SF earthquake aftermath) the code will require BX cable, metal jacket over three wires, the third being a dedicated ground wire--which is duplicated by the solid metal used in all the boxes and conduit.

The white wire is usually called 'Neutral' but also called "return" because there's nothing neutral about it. It still presents significant danger and often is improperly switched and energized.
The neutral lead can and should be tied back to the ground (earth, green or bare) lead at some point BUT THAT DOES NOT MEAN IT HAS BEEN. You can't assume that a ground ever has been made properly, or that work has been done "to code". You'll see a lot of professionals using a "sniffer" (looks like a pen) to actually test every wire and socket they are going to work on, even when they have disconnected the power from it. It is all too easy for someone to have taken a short cut, or made a mistake, leaving you with a lethal setup.
I found one (my friend asked for some help with a hanging house fixture that wasn't working right) where some clever soul had actually hooked up the return (white, neutral) TO THE METAL FIXTURE AND HANGING CHAIN because the real neutral wire had broken. Perfectly good...unless someone touched the fixture or chain while the light was turned on.
As they say, there's no sense trying to make things idiot proof, the good lord always has more time to build better idiots.

[cyan]

Originally Posted by hellosailor

"Wow, I'm really confused! I always thought that in the USA on 120 volt ac circuits. WHITE IS ALWAYS THE GROUNDED POWER CONDUCTER ( NUETRAL )"

Nope. Dangerous assumption to make, even if that is often how the wiring was done.

Your cautionary advice is good, but you are missing the point- a previous poster, billknny, wrote the opposite of the proper colors for the USA, calling it “standard wire codes”. This mistake caused big confusion among DIY types:
“Hot:White
Neutral:Black”
To be clear.
THIS IS WRONG
THIS IS WRONG
THIS IS WRONG.

Call it a typo or whatever, but before someone makes a big mistake, look up the USA colors. I assure you that hot should be BLACK, neutral should be WHITE.

[sandy stone]

Originally Posted by hellosailor

some clever soul had actually hooked up the return (white, neutral) TO THE METAL FIXTURE AND HANGING CHAIN because the real neutral wire had broken.

I don't intend this as criticism, I just want to clarify something in this already confusing and misleading thread. "Neutral" means the current-carrying return conductor (white), grounded at the "source" in the US. When you said the real neutral wire had broken, I assume you meant the safety ground wire (green or, usually, bare copper). It is confusing to call the safety ground wire neutral. I completely agree the situation you described was potentially dangerous.

[hellosailor]

cyan-
Not missing that point, just not responding to it. Responding to another one.

Sandy-
We sometimes have light fixtures wired up with just two wires, hot and neutral, with no ground connection from the socket (or junction box) to the device. Same as a two-wire extension cord. Since I was talking about the wire drop from the junction box to the light fixture (bulb), that's only a 2-wire run, and there's no ground wire in it. The ground wire *might* be attached at the junction box, but in that town, they allowed Romex and plastic boxes and for all I know, the real safety ground might only be connected at the main entry panel. Or, with the past owner's fiddling, not connected at all.

I had a six-volt AC discrepancy between ground and neutral in an apartment. Con Ed said "Yeah, we know all about that building, but it is not on the street side, the problem is in the building, we can't fix it."

Eventually someone convinced the owner that if the bad mains wiring kept going sparky sparky, the building could burn down, and since it was on record that Con Ed had warned him about that....Motivation.

But it all beats WW1 era cotton-covered wires on porcelain stand-offs. I had another friend who found THAT in their attic. Forget about "ground" entirely.

[deblen]

Originally Posted by a64pilot

I have a significant amount of what I am pretty share was factory installed DC wiring that is black (ground) and white (hot)
Is that a Marine standard?
AC on the same boat is black (hot) white (neutral) and green (ground)

The rule in North American marine DC wiring is(was?):


Black-always Negative DC



(negative DC is not necessarily the same as Ground & the Neg. DC is not intended to do the job of Ground)



The other colour (White,Red,etc) is Positive DC)


If you find a boat with it's DC colours opposite(black-pos. & white-neg) that boat was wired by a N. A. land lubber AC electrician.


EU uses a bunch of colours. You can google them.


/ Len

[dfelsent]

Originally Posted by deblen

The rule in North American marine DC wiring is(was?):


Black-always Negative DC



(negative DC is not necessarily the same as Ground & the Neg. DC is not intended to do the job of Ground)



The other colour (White,Red,etc) is Positive DC)


If you find a boat with it's DC colours opposite(black-pos. & white-neg) that boat was wired by a N. A. land lubber AC electrician.


EU uses a bunch of colours. You can google them.


/ Len

DC. Yes black is ground.

AC. Black is hot. Remember it by black is death.

If you don’t know what you are working on figure it out first by measuring. If you don’t know how to do that get help and maybe even training.

I’ve seen so much weirdness over the years I assume everything is mis-wired before I work on it.

I spent decades working with microvolts and picoamps to hundreds of kilovolts and kiloamps. Some of that stuff will kill you from a foot away.

Be safe, and learn.

[hlev00]

I started this thread but did not anticipate the amount of well intended but wrong information. Hopefully those that were misinformed now have the right info. I suggest we remove the thread to avoid anyone picking the wrong info. Thoughts?

[Zil]

in 120 volt ac wiring, yes the white is neutral, until you cut the white but not the black. then the white from the devise could be very hot to earth.



in low volt dc system black, or yellow or what ever code, is not ground, it is return to negative. In most automotive uses, the negative was part of the chassis return, but still not ground.