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Author Topic: Another power question - Black = x, Red = y?  (Read 49667 times)

Rick Stansby

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Another power question - Black = x, Red = y?
« on: May 30, 2007, 03:52:21 pm »

Okay so I'm making tails for my California Standard feeder (using a Leviton CS6364 and some 6/4 SO cable).  I usually plug this feeder into a generator, but at times I will want to have a qualified electrician tie me in to a panel.

I normally use Green for ground, White for Neutral, Black for X, Red for Y (and orange for Z on an L21-30).  

On the Cal Standard plugs and connectors the X is colored Red and Y is colored Black.  Don't ask me why.  In the past when making cables with a plug on one end and a connector on the other end I followed their wacky color scheme.  I figured it didn't matter as long as X on the plug was wired to X on the connector.  

With the tails I will only have a connector on one end of the cable with bare wires on the other end.  Ultimately I know it doesn't matter which leg is tied to which hot on the connector.  I'm running everything at 120, so as long as ground and neutral are right it doesn't really matter if X and Y are swapped.  Still I'm not sure which way to hook this up.  

I could put the red wire into the Y terminal (which is labeled black) then put the black wire into the X terminal (which is labeled Red).  Then the insulation on wires will tell the electician to put Black on X and Red on Y.  

Alternately I could follow the color convention on the connector, and let the electrician plug the red wire into Y, even though it is technically going to X on the Distro.

What would you do?

And who came up with the brilliant idea of swapping colors on this connector?
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Lee Patzius

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Re: Another power question - Black = x, Red = y?
« Reply #1 on: May 30, 2007, 11:56:36 pm »

Rick Stansby wrote on Wed, 30 May 2007 15:52


Alternately I could follow the color convention on the connector, and let the electrician plug the red wire into Y, even though it is technically going to X on the Distro.

What would you do?

And who came up with the brilliant idea of swapping colors on this connector?


As long as you are on a 240 Volt single phase system, it really doesn't matter what color is on the hot phase legs, except that you must use green (or bare) for ground and white (or grey) for neutral.

NOTE! Most cable tray rated cables I work with (OMNI Cable in an Ethanol Plant) don't even have a green or bare wire! So I use the closest color available... Blue.

It is always good practice to marry the phase legs, regardless of conflicting colors between connectors. So in your case I would force X,Y on the inlet to be X,Y on the outlet.

Note: Especially on three phase service. XYZ should be XYZ. I try to avoid XYZ=YZX or XYZ=ZXY, which still checks rotationally correct.

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Lee Patzius

 

Rick Stansby

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Re: Another power question - Black = x, Red = y?
« Reply #2 on: May 31, 2007, 02:05:49 am »

Lee Patzius wrote on Thu, 31 May 2007 04:56



It is always good practice to marry the phase legs, regardless of conflicting colors between connectors. So in your case I would force X,Y on the inlet to be X,Y on the outlet.

Note: Especially on three phase service. XYZ should be XYZ. I try to avoid XYZ=YZX or XYZ=ZXY, which still checks rotationally correct.




Lee,
Thanks.  I just wanted to make sure I wasn't missing anything.  

As you suggested I always make sure that all poles are "married" on any cable I build.  And I confirm this with a voltmeter after the cable has been assembled.  I do my best to stick with the conventions, but the colors don't mean a thing once the cable has been assembled. What really matters is that each pin is connected to its "soul mate" on the other end.

I ended up putting the red wire in the black hole (Y) and the black wire in the red hole (X). I figured once I assembled the connector nobody would see it or change it.  I'll probably make a little label that says "green=ground, white=neutral, black=x, red=y"
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Erik Jerde

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Re: Another power question - Black = x, Red = y?
« Reply #3 on: May 31, 2007, 01:09:47 pm »

Lee am I reading you right that you use blue for ground?  I've always run into blue as the third leg in a 3 phase system.  I'd think using blue for ground then could be a very bad thing.
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Ron Hebbard

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Re: Another power question - Black = x, Red = y?
« Reply #4 on: May 31, 2007, 01:22:51 pm »

Erik Jerde wrote on Thu, 31 May 2007 18:09

Lee am I reading you right that you use blue for ground?  I've always run into blue as the third leg in a 3 phase system.  I'd think using blue for ground then could be a very bad thing.


Hello Erik;

No, you're not reading Lee correctly, at least you're not reading him in context.

Yes, you're correct that using blue for ground, when green and/or bare are available, would be "a very bad thing".

Go back and re-read what Lee wrote.
Pay attention to the cable type.
Note that he's speaking of a specific situation where green is not available within the provided cables.
Also note that Lee's speaking of "cable tray rated cables installed within an ethanol plant".
I'd like to think that most electricians working in Lee's situation would have a handle on things and I'm sure he does.

Lee's a big boy and I suspect he'll be along to speak for himself but, again, no, I don't believe you're reading Lee correctly.

Toodleoo!
Ron Hebbard
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Vince Byrne

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Re: Another power question - Black = x, Red = y?
« Reply #5 on: May 31, 2007, 01:56:32 pm »

Erik Jerde wrote on Thu, 31 May 2007 12:09

Lee am I reading you right that you use blue for ground?  I've always run into blue as the third leg in a 3 phase system.  I'd think using blue for ground then could be a very bad thing.

Blue is either a Phase or Neutral depending on where you are in the world.

Per European harmonized cable standards:
Brown = L1
Black = L2
Grey  = L3
Blue = Neutral
Green/Yellow striped = Earth (safety ground)

Per NEC in the US:
Black = L1
Red   = L2
Blue  = L3
White = Neutral
Green or bare = Earth (safety ground)

Quote:

Note that he's speaking of a specific situation where green is not available within the provided cables.
In the industrial/service provider/customer premises worlds I play in, the electrical inspector wouldn't care much about the "provided cables" if I had safety ground on blue. He would shut down the job until it was green.

Of course I can't speak to an ethanol plant, not my world.

Suggesting Safety Ground on Blue could be okay in the context of an audio forum is unwise if not reckless. It certainly is confusing, is never correct for any audio application, and I wouldn't want to accept the liability.

Peace,
Vince
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Bruce Gering

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Re: Another power question - Black = x, Red = y?
« Reply #6 on: May 31, 2007, 06:46:35 pm »

Even though it's a good idea to have your lines run perfectly parrallel in single phase, it won't make a difference if you have the hookup swapped. In 3 phase, it will  because the pulse is moving in a pattern of 3. If XYZ is moving ZYX, an electric motor such as a rigging motor, will move backwards when the forward button is pushed. A quick swap of 2 hots will get you in the correct rotation.
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Sometimes I wish I had a clone of myself so I could enjoy life while my clone worked for me. Thing is, my clone would just keep the money, or worse yet, I would be working while he enjoyed my life!

Lee Patzius

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Re: Another power question - Black = x, Red = y?
« Reply #7 on: May 31, 2007, 07:55:36 pm »

index.php/fa/9458/0/

Vince Byrne wrote on Thu, 31 May 2007 13:56



Quote:

Note that he's speaking of a specific situation where green is not available within the provided cables.
In the industrial/service provider/customer premises worlds I play in, the electrical inspector wouldn't care much about the "provided cables" if I had safety ground on blue. He would shut down the job until it was green.


I'd like to see your inspector try to shut this project down. He'd have to answer to a lot of federal, state, and local government officials. Not to mention the ones who wrote "the book" (NEC).

This is specialized tray cable approved in class 1 and 2 hazardous (explosive) environments, and by OSHA, NEC, UL, IEEE, and a whole bunch of other jurisdictions. This plant is owned by the U.S. Federal Government and will continue to go through rigorous inspections on a continuous basis. There ain't no one shuttin' this baby down.

Quote:

Suggesting Safety Ground on Blue could be okay in the context of an audio forum is unwise if not reckless. It certainly is confusing, is never correct for any audio application, and I wouldn't want to accept the liability.


If green or bare is available, then use it. If you were forced to use approved tray cable (pasted above) then which color would YOU use?

Hint: According to the color code chart above, if you have #12 AWG 4 conductor (12-4) then the first 4 colors are available. If you use 12-7 then the first 7 colors are available, etc.

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Vince Byrne

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Re: Another power question - Black = x, Red = y?
« Reply #8 on: May 31, 2007, 11:59:52 pm »

Lee Patzius wrote on Thu, 31 May 2007 18:55

If green or bare is available, then use it. If you were forced to use approved tray cable (pasted above) then which color would YOU use?

Lee,

I have no reason not believe you that the ethanol plant application you describe meets applicable requirements. If it didn't, it wouldn't be done that way, right? Smile

What I don't see is how one would/could be "forced" to use the cable in your example for an AC circuit in an audio related application. Are you suggesting that an AC circuit with the #12 AWG 4 conductor (12-4) with colors Black/Blue/Red/Orange with ground on Blue would be allowed per the NEC for an audio application? I'm open to learning something new here, but this goes against everything I've seen or heard in 19 years of power system design.

Peace,
Vince
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Lee Patzius

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Re: Another power question - Black = x, Red = y?
« Reply #9 on: June 01, 2007, 01:41:17 am »

Vince Byrne wrote on Thu, 31 May 2007 23:59


I have no reason not believe you that the ethanol plant application you describe meets applicable requirements. If it didn't, it wouldn't be done that way, right? Smile


Right, the amount of engineering that went into this place is mind boggling. Everything is spec'd out to the finest detail in print, down to individual cable, wire type, grounding and terminal numbers. Thousands upon thousands of terminations, color codes, and polarities, all in compliance with federal regulations etc. And on-the-fly mods are drawn as built, to engineering specs as well.

Quote:

 What I don't see is how one would/could be "forced" to use the cable in your example for an AC circuit in an audio related application.


I haven't seen nontraditional color codes in audio or stage power cable. So green or bare, which are readily available, get grounded.

Quote:

Are you suggesting that an AC circuit with the #12 AWG 4 conductor (12-4) with colors Black/Blue/Red/Orange with ground on Blue would be allowed per the NEC for an audio application?


If you run THIS Omni tray cable for a permanent install, laid exposed in a cable tray, then yes. You must pick a color for ground. Since it has no green you must use something. The color code for this particular type tray cable, at our ethanol plant, is as follows:

12-3 for 120VAC Power
Black = Hot
Red = Neutral
Blue = Ground

12-4 for 120VAC with Switched Hot Signal
Black = Constant Hot
Red = Neutral
Blue = Ground
Orange = Hot or Switched Hot

12-7 for 480VAC 3 phase Motors with 120V Hand-Off-Auto (HOA) switch
Black = Hot 120V HOA switch Hand-Auto mode jumper common
Red = Switched Hot "Auto" mode
Red/Black Stripe = Switched Hot "Hand" mode
Brown = 480 Vac Phase Leg 1
Orange = 480 Vac Phase Leg 2
Yellow = 480 Vac Phase Leg 3
Blue = Ground

Note: You can't use 12-7 for HOA and 480 Volt motors with Varaiable Frequency Drives (VFD) or inverters, due to harmonic bleed, even WITH line reactors.  

Quote:

 I'm open to learning something new here, but this goes against everything I've seen or heard in 19 years of power system design.


In this particular ethanol plant, it's a government research center. We do on-the-fly heavy equipment and power modifications per client requests. There's an awful lot of ethanol recipes and processes brewing out there. I seriously learn new stuff every day.

It's a wonder how I manage to play out in two bands and hold down my day job with the US government. I own a hair salon too! Believe it or not.
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Lee Patzius

 
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