white wire used for hot

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doodman

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Recently I was asked to wire several banks of A/C condensors using MC cable. All of the units were 3 phase 240 volt ranging from 20 to 25 amps. I took measurements to see how much MC I needed and ordered several thousand feet of 10/3 MC.
When my cable arrived I was read the riot act for not ordering 10/4 and told I wasnt allowed to use the white wire in MC for anything except a grounded conductor and wasnt allowed to phase any wire under a #6. Since I was already in hot water I asked where in the code could I find that article (so I didnt do it again) but nobody could find it. I found an article that said I could use a wire normally used as grounded for an un-grounded conductor if I permanantly marked it wherever visible and accessible, and another article that said i wasnt to phase a wire smaller than #6 for use as a grounded conductor.
I really think I'm right and its a lot of wire to send back and 10/4 costs a whole lot more. Someone give me some input so I can be sure I'm right before I go back and tell the people in charge that I am right or that they were right.
 
Re: white wire used for hot

You are correct.

200.7(C)Circuits of 50 Volts or More. The use of insulation that is white or gray or that has three continuous white stripes for other than a grounded conductor for circuits of 50 volts or more shall be permitted only as in (1) through (3).

(1)If part of a cable assembly and where the insulation is permanently reidentified to indicate its use as an ungrounded conductor, by painting or other effective means at its termination, and at each location where the conductor is visible and accessible
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In a cable you can do this, in a raceway no you may not.
 
Re: white wire used for hot

Those that were so anxious to criticize you should be polishing their apology tonight.

You can re identify the white conductor for use as an ungrounded conductor in any size
cable assembly if you follow 210.7(C)(1 thru 3)as Bob points out.

Roger
 
Re: white wire used for hot

Just a thought......
Several K of cable? Have you done a volt drop calc? Those units may only use up to 25 amps but don't forget startup draw is much higher, and the longer the run the more that is a problem. At 25 amp. if you are 100' away from the panel and use #10 I show a 4.5% VD, not even counting startup draw.
RAW
 
Re: white wire used for hot

Originally posted by iwire:
You are correct.

200.7(C)Circuits of 50 Volts or More. The use of insulation that is white or gray or that has three continuous white stripes for other than a grounded conductor for circuits of 50 volts or more shall be permitted only as in (1) through (3).

(1)If part of a cable assembly and where the insulation is permanently reidentified to indicate its use as an ungrounded conductor, by painting or other effective means at its termination, and at each location where the conductor is visible and accessible
Click to expand...
In a cable you can do this, in a raceway no you may not.
Click to expand...


Unless your willing to identify the entire conductor were visible
 
Re: white wire used for hot

Megawire,
Unless your willing to identify the entire conductor were visible
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where is this stated? 200.7(C)(1 thru 3) are for "cable assemblies" and "flexible cords"

Roger
 
Re: white wire used for hot

Although this is permitted, I think it is a very bad practice and should only be done in emergencies.
 
Re: white wire used for hot

Originally posted by cormier_paul:
Although this is permitted, I think it is a very bad practice and should only be done in emergencies.
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Do you mean using the white as a hot in a raceway which is an NEC violation or do you mean relabeling the white in a cable or cord which is allowed?

I can not speak for anyone else but I will not be buying 12/4 MC just so I do not have to relabel the white for straight 3 phase equipment. ;)

It is allowed and anyone jumping in boxes assuming white is dead is their own worst enemy.
 
Re: white wire used for hot

Bob,
I can not speak for anyone else but I will not be buying 12/4 MC just so I do not have to relabel the white for straight 3 phase equipment. ;)
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nor will I.

It is allowed and anyone jumping in boxes assuming white is dead is their own worst enemy.
Click to expand...
AMEN.

Roger
 
Re: white wire used for hot

Originally posted by cormier_paul: Emergency = You?re in the middle of nowhere and need repaired immediately.
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That I would call an ?abnormal situation? (Bryan's comment notwithstanding ;) ), or perhaps just an ?inconvenience,? but not an ?emergency situation.? A person experiencing electrical shock, a hospital losing the utility power and the diesels don?t start, an arcing ground fault that is about to set the carpet on fire, a power line falling onto an occupied vehicle: these are emergencies. In my book, for a situation to be called ?an emergency,? it must present an immediate threat to life or property.

Here?s the difference: If the situation causes you to ?cut corners,? to do something out-of-the-ordinary, in order to satisfy the immediate need, but you are willing to leave it that way, even after the situation is no longer time-critical, then it was not an emergency. On the other hand, you might have to do something out-of-the-ordinary, in order to protect life or property during a true ?emergency,? but when the emergency has passed, you go back and rip it out and do it over properly.

I?ll step off the soap box now. I just wanted to discourage the practice of saying, after the fact, that ?I had to do it that way; it was an emergency.?

[ May 04, 2004, 10:35 AM: Message edited by: charlie b ]
 
Re: white wire used for hot

Technically, an emergency would not justify an unsafe practice - even a "temporary" one. See Section 527.3 (C) and interpret it in light of 527.2.

That being said, it is important to realize there is no inherent danger in the installation originally under discussion; i.e., the color of a conductor itself would not cause ??hazards arising from the use of electricity.? If it were a hard safety issue we wouldn?t permit any exceptions at all. Color coding is a practice to increase safety - not create it.

So we are now down to the basic purpose of the Code: ?The purpose of this Code is the practical safeguarding of persons and property from hazards arising from the use of electricity.? (Section 90.1 Bold added )

The entire Code needs to be interpreted in this light. When we are considering safe vs. unsafe a clear line is drawn ? an inherently unsafe practice is not permitted under any condition ? even an emergency. When we are considering save vs. safer we may consider ?the practical? economics such as cost, availability of product, time constraints, training, signage etc. In other words, properly identifying a white conductor in a cable as an energized conductor meets all real safety requirements and is a practical method to achieve it.
 
Re: white wire used for hot

My final comment on this topic;

Its poor practice, just like splicing inside a LB fitting which you are also allowed to do. Do it if you have to, but dont make it the norm!!
 
Re: white wire used for hot

Originally posted by cormier_paul:
My final comment on this topic;

Its poor practice, just like splicing inside a LB fitting which you are also allowed to do. Do it if you have to, but dont make it the norm!!
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Please comment more, tell us what kind of work you do where you can buy cables with extra conductors just so you do not have to relabel the white as a 'hot'.

Can you explain why you feel it is a 'poor practice" and what your alternative method is?
 
Re: white wire used for hot

Paul, please do tell, I'm curious like Iwire, what type of work do you do?

Have you ever used NM in an installation.

As far as making splices in an LB, they make receptacles (or did) that would install in an LB, so why is this a poor practice?

Are these methods your just not familiar with?

Roger
 
Re: white wire used for hot

I would like to know how he stays in business with buying all the extra material.... Competition is tough out there and is pretty cut throat.
 
Re: white wire used for hot

Originally posted by r_bachle:
I would like to know how he stays in business with buying all the extra material.... Competition is tough out there and is pretty cut throat.
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Ditto

Roger
 
Re: white wire used for hot

No one should ever make an assumption based on wire insulation color. I never assume color means anything. When I hear people making broad statements about what certain colors mean I get uneasy. I recently installed a 500 hp tube reducer that had run in Italy before coming to the States. The bus bars in the power cubical were marked yellow, purple and green. Green being the 3rd phase. Go figure!
 
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