Electricians: can neutral be anything but white?

[buickanddeere]

I'm with you on this and as someone who still works in the trade from time to time, I applaud you for being hard-headed on some things. I am the same way. I'll walk away from a job if the customer refuses to take sound advice from an experienced perspective because 9 times out of 10 there is trouble coming sooner or later and they will blame me.
Now, about the 220V going through 110 appliances, I have seen it happen and do over $160,000 damage in a hotel resort I was working on. The plumbing contractor cut the neutral in the main with a backhoe and every TV, phone and clock radio was fried. There was not a single shared neutral in the place. And it is not necessary to have shared neutral to get the 220 if the neutral is severed before the breaker box in the circuit. Every appliance that is turned on will act as a pathway for the two phases to re-unite.

Correct except in single phase it's called Line 1 and Line 2. Three phase power does refer to phases.

 

[buickanddeere]

opcorntub::beer::antacid:

Only if the neutral cable is larger than 4/000.

 

[buickanddeere]

If being a rude blowhard is somebody that calls out unsafe behavior by pig headed people who just have to do it their way. So be it.
The degree of adherence to the National Electrical Code varies from jurisdiction to jurisdiction. What maybe tolerated in Hicky Sticks or Podunk is not legal where safety is held in a higher priority.

 

[LD1]

I didnt see anyone here propose unsafe behavior. And didnt see anyone here propose doing something that was not up to code. So who cares if we dont use the correct terminology.

The fact that 240v uses 2 hot "legs" and some of us refer to them as phases....who cares. So when I say on a MWBC as long as the neutral is share between hots on different phases, while it may not be correct terminology, it is still correct wiring and NOT unsafe. And it seems to make more since than saying "make sure the neutral is shared between two different hot lines". Because anyone else googling and/or reading this thread may get the wrong assumption that "line" just means two different 120v lines, and not necessarily two that are 180 degrees out of "phase"

When I wire up a phase converter or VFD with the two 240v legs, is it okay to call them phases then? or is it only okay to call the two lines (+ created leg) phases AFTER the converter?

My questions and reasons for starting this thread were to better understand a MWBC. I know how to wire them, and know how they work, and have worked on them many times in the various factories I have worked at. Just never paid attention to how GFI's get tied in. So with the help here, I now understand.

I also didnt know if code allowed anything other than white for neutral. This is my barn, with no inspections or code enforcement. I could use pink or brown, or blue, freaking rainbow color wire and no one can stop me and no one will care. But even though I am not forced to follow code, I want to. That question was answered as well.

Back on page 7 I said I had my mind made up. But never said which way I was going to go (intentionally). I am not gonna be doing a MWBC. I would only be saving basically 1 run of wire around the shop. While I would save 2 wires in theory, thats only to the first outlet, which is only 3 feet from the main. Then I would have to add a neutral for that GFI circuit. With all the circuits being GFI, everytime I start a new circuit, I add a ground. So only saving what is equal to 1 run of wire, and risk of 240v, I am going to do a typical install.

 

[caver]

This is my barn, with no inspections or code enforcement. I could use pink or brown, or blue, freaking rainbow color wire and no one can stop me and no one will care.

Back in the late 80's my co-worker and I went to this small rural industrial site that made stuff like ANFO for the blasting industry.
One of the three phase 480 auger motors was wired with three green #12's. I guess someone really wanted to finish that circuit and ran out of wire.

 

[LD1]

Did they at least use coding tape?

 

[Fawken]

I didnt see anyone here propose unsafe behavior. And didnt see anyone here propose doing something that was not up to code. So who cares if we dont use the correct terminology.

The fact that 240v uses 2 hot "legs" and some of us refer to them as phases....who cares. So when I say on a MWBC as long as the neutral is share between hots on different phases, while it may not be correct terminology, it is still correct wiring and NOT unsafe. And it seems to make more since than saying "make sure the neutral is shared between two different hot lines". Because anyone else googling and/or reading this thread may get the wrong assumption that "line" just means two different 120v lines, and not necessarily two that are 180 degrees out of "phase"

When I wire up a phase converter or VFD with the two 240v legs, is it okay to call them phases then? or is it only okay to call the two lines (+ created leg) phases AFTER the converter?

My questions and reasons for starting this thread were to better understand a MWBC. I know how to wire them, and know how they work, and have worked on them many times in the various factories I have worked at. Just never paid attention to how GFI's get tied in. So with the help here, I now understand.

I also didnt know if code allowed anything other than white for neutral. This is my barn, with no inspections or code enforcement. I could use pink or brown, or blue, freaking rainbow color wire and no one can stop me and no one will care. But even though I am not forced to follow code, I want to. That question was answered as well.

Back on page 7 I said I had my mind made up. But never said which way I was going to go (intentionally). I am not gonna be doing a MWBC. I would only be saving basically 1 run of wire around the shop. While I would save 2 wires in theory, thats only to the first outlet, which is only 3 feet from the main. Then I would have to add a neutral for that GFI circuit. With all the circuits being GFI, everytime I start a new circuit, I add a ground. So only saving what is equal to 1 run of wire, and risk of 240v, I am going to do a typical install.

I think you'll be happier with that from the standpoint of branching out later down the line. And not messing with tied breakers. BTW, I'll still do the current testing, but after rethinking the actual behavior of an AC circuit I can now see how some of the voltage from one side of the line can reunite with the other side without returning through the neutral. To tell you the truth, I never really thought about it and didn't have reason to.

 

[LD1]

Looking forward to your tests.

Running a mwbc with shared neutral is no different than the power coming to your box from the meter/xfmr. (2)/120v legs with ONE neutral.

That neutral will NEVER see more current than what is one ONE single leg. It is NOT additive.

In fact, the service entrance can have a downsized neutral in most cases. And the only way to overload it would be to pull the max off a single leg and NONE from the other. Which would be very unlikely. It don't matter if you pull 10 amps from each leg, or 200 from each leg. If what you are pulling is equal, amps on neutral will be zero. If its not equal, neutral only sees the difference

 

[ultrarunner]

About 20 years ago the power company replaced all the drops from the poles to the meter weatherheads...

All the drops now have a downsized bare neutral.... even of the homes that have never been upgraded to 240v service... said it was less expensive to standardize...

 

[caver]

Did they at least use coding tape?

Nope.