Does 210.5(c)(1) mean that even switchlegs and travellers need to be the same color as that designated for the phase feeding them? Thus, I may have 5-10 or more conductors of the same color in the same junction boxes of one room. Obviously, it works much better to use, for instance, pinks and purples for travellers and the two remaining phase colors (other than the feed color) as switch legs.

Is this a place served by "more than one nominal voltage system"?
If not, this does not apply.

*** Opinion bit on***

Even if it did, I would still use tape to give these conductors supplementary identification.

For example we could have 3p 480 indicated "BOY"
and the 3p 208 would be Bk,R,Bl

If I was running a switch loop on the black phase I would use black conductors and put a wrap of pink and purple tape on the travelers if that is your convention.
I think we are trying to convey more information identifying conductors, not less. You just have to stay away from green, gray and white on ungrounded conductors.

*** opinion off ***

This is still new to me. Florida is still on the 08 and unless they do something radical for them we won't get the 11 until March of 15

210.5(c) Tells you that ungrounded conductors need to be identified according to 210.5(c) (1), (2), and (3) (all 3)

210.5(c) (1) Tells you when. (If there is more than 1nominal voltage on premises.

210.5(c) (2) Tells you the acceptable means. (separate color coding,marking tape, tagging, or other approved means.)

And 210.5(c) (3) tells you how to let everyone know what you did to identify the voltages.

All things being equal; yes, that IS what it is saying.

I hope you can continue to use different colors for the travelers, different switches, etc. It sure can make things less confusing.

That said, there's a limit to what you can do with colors. You CANT'T have it ALL! That is, clear wiring, minimal wire, minimal box count, etc. Let's look at two ways to do a 3-way switch arrangement:

A very common way is to have the power feed directly to the box over the fixture, with 'switch legs' going to the two switches. This results in all the wire nuts being in one box. It also means that the white wires going to the switches are used as part of the switch leg. The result can be a pretty crowded box, with all the wires looking the same.

Perhaps it would be better if you ran your power to the first switch, instead of directly to the fixture. Then run a cable with an extra wire to the next switch; there are your travelers. Finally, run wire from the last switch to the fixture box.

(This arrangement makes connections pretty clear in each box, and provides a neutral at each switch as well. IMO, this is the layout the Code is trying to encourage).

"But I don't have 2-circuit cable on the truck." Like I said, you cant have everything.

With the advent of energy codes, and more complex switching
arrangements, the problem can get even worse. Let me give an example of a job I did:

A meeting room had twenty 4-bulb fluorescent lights. They were to be controlled by two sets of 3-ways, so as to provide "two levels of lighting." The joker in the deck was that it was not clear exactly HOW they wanted the two levels of lighting achieved.

My plan: A small departure from the usual color coding arrangement. While power to each 'first' switch was from the same blue wire, I used blue and red from the "last" switches to the lights. I used purple (blue) and pink (red) for the travelers. In addition, I used the little lever-type Wago connectors. This allowed for easily changing the switching layout- much easier than using wire nuts.

How did it work out? Well, I made my best guess and powered up the lights. I guessed pretty well; I only had to move two lights from one 'set' to the other.

IMO, any understanding of the Code that would ban this method would be creating a hazard, not eliminating one.

Mandating a color code is not the intention of this code section. It simply suggests colors as one method of identifying voltages . You could just put little tags on all of the wires in your different systems and write "208/120" and "480/277" on them and meet this code requirement. Or you could use all purple wires for one system and all yellow wires for another. That would be a little redonkulous but would satisfy the requirement.

I still see nothing in the code that prevents putting an additional color on the travelers with a ring of tape. The base conductor color would still be compliant and make it clear what phase you were dealing with and the tape would identify each conductor separately.

This code rule is going to make it pretty hard to use a cable wiring method in any building it applies to unless the manufactures add different color combinations to their product line. What are you going to use for whips to troffers on C phase? Have you seen blue/white MC?

From Southwire site....

http://www.southwire.com/ProductCatalog/XTEInterfaceServlet?contentKey=prodcatsheet66

You may be able to find 'other' colors as a special order, if $$$ is no object.

I see MC there aimed at the 480/277 circuits but nothing for 120/208/240 if you want something other than black/white and adding phases from there.

I think this change in 2011 should have exempted 120v circuits at the branch circuit level, perhaps only for switch legs.
It did not change in 2014

I can understand wanting to identify 480/277 circuits but BOY on the line to line and the purple/gray 277 seemed to do a pretty good job. They should have just codified that.

The only confusion with that is if you had 480 wye and a center tapped 240v delta.
I think that would be so rare that it is not an issue tho.

Are you talking about a high leg? 480 primary with a 120/240 secondary?

110.15 High-Leg Marking. (Orange or other effective marking)

Sorry about that last post. I'm having issues with my phone. 😕

Yes I was speaking of the orange but I meant two services with different voltages.

Of you use it for the 480, it would be confusing as the high leg of the 240.
I really doubt you would see both in one place.
The reality is that you usually only see high leg delta in places where there is a limited need for 3 phase and the PoCo is giving them the cheapest alternative. I have only seen one 240 delta with 3 transformers in 20 years of looking at them.
I assume they grew into it and did not want to rewire their equipment. It is behind the Hogs Breath in Key West and serves a couple customers.
Usually I see a big one for the 120/240 loads and a little one for the high leg.
I guess it might be different in other places.

I know of no situation with our Pocos where it's actually possible to have 480Y277 service AND 240 center-tapped delta.

Indeed, EUSERC has put the hammer down on 240 center-tapped delta. It's being phased out across the board. Legacy system still exist for older structures, though. Don't get your hopes up if you expect to bid and wire a new installation.

&&&

One of the factors that many j-men forget/ ignore is that the neutral for 480Y277 and a derived 208Y120 are 30 degrees out of phase -- with the derived current lagging.

This is noted in every Ugly's -- but its in the fine print.

THIS is the reason why your grays and whites can't get crossed over. You'd end up with an amazing harmonic on the returns.

And, in the same vein, it's a disaster if a hot for BOY is mated to the return for BkRBlu. You'll get wicked harmonics, too.

Those are the conductors that end up getting fried... first.

You might also have your returns undersized, as a result.

In commercial installations, it's my practice to just keep lighting circuits separate from everything else. I isolate them regardless of the Service voltage.

HVAC and lighting are the only loads fed by 480Y277V in commercial practice -- with exceptions for weird equipment, and the elevator system. And those exceptions are really rare.

Industrial is loaded with 480 delta motor loads -- which have largely replaced everything that has come before. With rare exception, I isolate my control circuits. Experience has caused me to shun 480/ 240/ 208 double-pole control relay voltages. They get too much dynamic feed-back from motor EMF.

So, outside of service work, I don't expect to face these troubles.

I think that is how "gray" got to be the defacto 480 neutral color, long before the NEC actually made it legal.

Prior to 2002 we were always arguing whether the gray was "natural" enough to be used for a neutral.