Phase Coloring

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brandon2177k

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Okay, I know a 208/120Y 3 phase system is colored Black, Red, Blue for each phase. And, a 480/277 3 Phase system Brown, Orange, Yellow. Now, if you have a 240/120 delta 3 Phase, your high leg(B Phase) should be Orange, but what colors identify Phase A, and Phase C? Also, can you have a 240/120 3Phase Y system? And what is the coloring of each Phase? Thanks in Advanace.
 
growler said:
What about gray. I like gray.
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How do you feel about red?
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Growler, if it were in an area under an NEC cycle prior to 2002, gray could be used for the ungrounded conductors.

Brandon, to go a little further with Bryans post, the colors you mention for the two systems are just trade practices but not in the NEC for standard systems.

There are color codes in the NEC for certain things and even Brown, Orange, Yellow, is a code mandated color code, but this would be for Isolated Power systems in hospitals only.

Roger
 
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Roger you are correct as usual. I forget that some areas are still using older versions of the code. I have been working in state for the past few years I guess I need to get out more.
 
brandon2177k said:
Also, can you have a 240/120 3Phase Y system?
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No, the laws of physics won't allow it. A 240/120 3-phase system would have to be connected in a Delta configuration giving you two phases at 120-volts to neutral and one phase 208 to neutral.
 
Growler, if it weren't for being involved in the forums and hearing others talk about being under older cycles, I certainly wouldn't think of these other situations either.:)

I'm like you, NC adopts the new NEC pretty quickly each cycle.

Roger
 
Roger I'm going to back up on this one as I just got out my 1996 Code Book.
200-7 Use of white or Natural Gray Color: A continious white or natural gray covering on a conductor or a ( termination marking ) of white or natural gray color ( shall be ) used for used only for the grounded conductor.
 
Ah yes Growler, the old "natural Gray" color. It didn't really exist in modern wire colors. :) Read the FPN to 200.7(3)(C)in the 02.

Roger
 
Technically you are correct Roger. Since 1923 the term Natural Gray was used in the NEC to distinguish a grounded conductor. But there was never an accurate description of what was natural gray ( it could be dark or light, the NEC Digest ). It only took 80 years to figure out that this could cause some confusion. Even though it was not specifically forbidden to use gray as a hot conductor in the code I think that most people reserved it for neutral on 480 V, three phase multiwire circuits ( got that from Southwire ). So if these people haven't adoped the 2002 Code yet they can use gray as an ungrounded conductor but they would have to be the South end of a North bound horse to do so.

Voltaire: Common sence is not all that common.
 
brandon2177k said:
Okay, I know a 208/120Y 3 phase system is colored Black, Red, Blue for each phase. And, a 480/277 3 Phase system Brown, Orange, Yellow. Now, if you have a 240/120 delta 3 Phase, your high leg(B Phase) should be Orange, but what colors identify Phase A, and Phase C? Also, can you have a 240/120 3Phase Y system? And what is the coloring of each Phase? Thanks in Advanace.
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Brandon, as the others have said, the NEC does not address colors other than grounded conductors and the 208 volt "High" leg. But, I usually use Black for the "A" ? and Blue for the "C" ?
 
Minuteman said:
Brandon, as the others have said, the NEC does not address colors other than grounded conductors and the 208 volt "High" leg. But, I usually use Black for the "A" ? and Blue for the "C" ?
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Hmm...

Though I don't run into it all that often (only once in the last ten years) I use Black for A? and Red for C?, because A-N-C is 240/120V, 1?, 3W.
 
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