Looking for code requiring 3 different colors for 3 different phases

[Fred B]

It seems silly to have to identify phase for single phase loads.

Other than avoiding two different 277V phases in a switch box, why would I care what phase a lightbulb is on?

Jon

Well other than trying to balance loads that can more critical for backup generator setup, phasing of the split phase 120/240 single pole circuits can be desirable. But with common residential use, truly fully balanced loads not really achievable, as various loads applied or turned off at different times.

 

[kwired]

Which voltage system maybe is a good idea. Which "phase" sometimes doesn't matter much at all. Balancing - maybe more handy with single phase loads, especially if a lot of line to neutral loads.

Three phase loads are almost always already balanced in nature. So are straight 240 volt loads on a single phase supply - I could care less which line connects to A and which to B in those applications.

IMO this is one place where NEC is encroaching on being a design manual which it claims it is not intended to be. Some instances this might be good design, some applications it might not really matter and isn't going to make a drastic difference on safety of the install. That said most my comments have been based on what it does say though.

 

[tortuga]

200.6 gets more complicated when you have DC conductors over 60 Volts or whatever, and they want to use red and black for DC.
Or when you have 480/277 and a 240/120 Delta and both systems want to use orange for 'B'

 

[paulengr]

Whether it’s Code or not, convention does matter. A lot less mistakes get made if you follow convention.

Example: I was supposed to install a 480 V VFD. The water plant staff ASSUMED the booster station was 480 because that’s what the city engineer said. I opened a starter to find black orange red. Hmm, unusual but the B phase orange made me suspicious and I immediately confirmed it was high leg delta. So the 480 vFD went back with me.

 

[kwired]

200.6 gets more complicated when you have DC conductors over 60 Volts or whatever, and they want to use red and black for DC.
Or when you have 480/277 and a 240/120 Delta and both systems want to use orange for 'B'

There is 480 volt high leg delta as well. Not real common but does exist. 240 to ground on two legs and 416 on the other.

 

[4x4dually]

Whether color differentiation is required by code or not, I'm confused as to why anyone would ask if the conductors could be all black. Why would anyone purposely not color them, regardless of whether they used the normal color convention or not. Just curious.

 

[kwired]

Whether color differentiation is required by code or not, I'm confused as to why anyone would ask if the conductors could be all black. Why would anyone purposely not color them, regardless of whether they used the normal color convention or not. Just curious.

forget about having multiple voltage systems for the time being.

If you running a circuit to a balanced three phase load where input phase rotation doesn't matter, why do you care which phase is which?

Such loads might be three phase heater, a VFD or anything else that is immediately rectified to DC volts. None of those really matter what phase conductor goes where.

If running three such circuits in one raceway I'd rather use three blacks for one circuit, three reds, for one circuit and three blues for one circuit than to have to run one of each color per circuit then have to further identify which black/red/blue went with which circuit.

 

[ActionDave]

Whether color differentiation is required by code or not, I'm confused as to why anyone would ask if the conductors could be all black. Why would anyone purposely not color them, regardless of whether they used the normal color convention or not. Just curious.

For one thing it cures one of being a lazy, paint by number electrician or sticking their fingers somewhere they shouldn't.

I generally dislike color code requirements. I've been known to pull one color for a live and an off color for a switch leg, or for line and load at a disconnect. As another example, I also like to use all black for one motor and all blue for a second motor when the conductors originate in a common pipe.

 

[4x4dually]

If you running a circuit to a balanced three phase load where input phase rotation doesn't matter, why do you care which phase is which?

Call me OCD I guess. Does it matter? Absolutely not. Do I consider it best practice? Possibly.

 

[4x4dually]

For one thing it cures one of being a lazy, paint by number electrician or sticking their fingers somewhere they shouldn't.

I generally dislike color code requirements. I've been known to pull one color for a live and an off color for a switch leg, or for line and load at a disconnect. As another example, I also like to use all black for one motor and all blue for a second motor when the conductors originate in a common pipe.

I can see that. I guess I was considering the lack of 'phasing' with color to be in the lazy category. I can see your synario and that being useful.

Disregard my thoughts. LOL

 

[tom baker]

210.5(C) requires identification by phase and voltage. All 3 phases of the 240 volt system cannot be the same color. That same with the 480 volt system. The identification by system will prohibit the same color from being used in both systems.

Yes I missed that

 

[tom baker]

Would numbers and tagging only be required with more than one nominal voltage system on premises?
This sort of reiterates my other question but I am looking for clarity.

Identification of phases is required by phase or line only if more than one voltage is on premises?
And let’s include the properly identified factory manufactured natural grey grounded conductor in our hypothetical service so everyone can be comfortable

Natural gray is no longer an color option for the neutral. It was changed to white or gray, or three white or gray stripes. as no one knew what natural gray was (maybe old rubber wire was natural gray), but we all read natural gray to be gray.

 

[tortuga]

All 3 phases of the 240 volt system cannot be the same color.

Thats not what 210.5(C) says.

 

[tortuga]

NEC doesn't specify any particular method, just that you need to identify system and phase when there is more than one system on the premises.

That is correct

 

[Mr. Serious]

Natural gray is no longer an color option for the neutral. It was changed to white or gray, or three white or gray stripes. as no one knew what natural gray was (maybe old rubber wire was natural gray), but we all read natural gray to be gray.

I don't know either, but I do know when I was an apprentice the company I worked for had some gray wire that was pretty dark, and in poor lighting, it looked black. Nobody wanted to use it because according to the NEC it should be a neutral, but it looked black. If you got it in the sunlight or under really bright lights, you could tell that it was dark gray, not black.

I started using it in place of black wires in poorly-lit areas and eventually used up all of it in that fashion.

 

[tortuga]

the company I worked for had some gray wire that was pretty dark, and in poor lighting, it looked black.

Yeah I have had a batches like that.
I was never a fan of that change, you used to be able to order light gray or natural gray, like you can order light blue.
I have not seen 'light gray' as a ordering option lately.

 

[Knipex Dream]

Okay let’s do an inspection. Code requirements or prohibitions only.

A building/premise has more than one voltage. A 3 phase feed to a rooftop air equipment has the voltage and 3 phase identification permanently fixed on the outside. The disconnect has L1 L2 L3 on three identical conductors whose insulation is code compliant as ungrounded.
Is the requirement to be identified by phase and line met or do the 3 phases need to be differentiated?

Again, I am only interested in the code. I assure everyone I am also interested in good practice and making things easier but for here I only want the requirements or prohibitions to the letter of the law.

 

[ActionDave]

They can be the same color but the three phases need to be identified in a consistent manner throughout the building. 210.5(C)(1). If you don't want to use colors then you'd need tag all the phase conductors at all termination or splice points.

 

[roger]

Okay let’s do an inspection. Code requirements or prohibitions only.

A building/premise has more than one voltage. A 3 phase feed to a rooftop air equipment has the voltage and 3 phase identification permanently fixed on the outside. The disconnect has L1 L2 L3 on three identical conductors whose insulation is code compliant as ungrounded.
Is the requirement to be identified by phase and line met or do the 3 phases need to be differentiated?

Again, I am only interested in the code. I assure everyone I am also interested in good practice and making things easier but for here I only want the requirements or prohibitions to the letter of the law.

For more than one system present the systems including individual phases must be identified and labeled something like below.

 

[kwired]

What Roger posted is probably the most common method you will see. It is not the only method. As been mentioned many times code only says you need to distinguish system and phase, it doesn't give any indication or requirement of how you do that.