These coloring schemes don't make the system work one bit better.
Sure it does!!! The Electrons will only flow through a color coded conductor
I am just playing around here - by no means am I flaming you Tom! It's just a joke that I use on the job to see if someone is listening to me or just blowing sunshine up my butt.
Believe it or not, I have gotten a few responses that agreed with the bogus theory...and they were serious!!! Wooo...scarry [Count Floyd - SCTV].
It's funny to see the reaction of people when you throw that one at them! There's this puzzled look and a temporary loss of words, but I clue them into the joke before disaster sets in [disaster= running at mach speed to the owner, informing them of the quack EE / Electrician on their project].
As Tom has explained, there's no real color code in the NEC. It only requires Grounded Conductors to be either White or Gray [was "natural gray" in previous versions, but natural gray looks like any old gray to me!],
Equipment Grounding Conductors to be Green, Green w/ yellow threads (yellow stripes) - commonly used for Isolated Grounds, or can be bare [in the nude
Lastly, the High Voltage [to ground] line on a 4 wire delta is to be Orange.
Other than the listed Conductors above, the NEC doesn't care if you used a conductor with cute little polka dots on a Black/Pink/Purple Tie Dye colored insulation
There is a "commonly used color code" that's used in the trade, which Tom has described also.
For 1 phase 3 wire [120/240 v 1 ph 3 w], Black would be for Line "A", Red for Line "B", White for the Grounded Neutral.
For 208Y/120 3 phase 4 wire:
Line "A" = Black, "B" = Red, "C" = Blue.
Common / Grounded Conductor = White
For 120/240 3 phase 4 wire Deltas:
[*] In service equipment: "A" = Black, "B" = Blue, "C" = Orange (the High Voltage Line)
[*] Other than Service equipment, or everywhere else: "A" = Black, "B" = Orange (the High Voltage Line), "C" = Blue.
The Grounded Neutral is White.
For 480Y/277 3 phase 4 wire:
"A" = Brown, "B" = Yellow, "C" = Orange [AKA BOY].
Common / Grounded Conductor is Gray.
A person in another forum a few years back made a very important point regarding the color coding of "C" on this system, when there's a low voltage SDS on site that is a 4 wire Delta [kind of rare, but not impossible].
The color coded Orange wire would be best suited for the 4 wire Delta's "B" phase, then change the "C" phase on the 480Y/277 system from Orange to Purple.
Right after the person mentioned this, I had some T.I. work in an older Commercial area - which had two Utility services: one 480Y277, the other 120/240 Delta!
Lastly, for 3 phase 3 wire systems:
"A" = Black, "B" = Red, "C" = Blue is the "universal" color code for any voltage.
**BTW** If the system is a "corner grounded" Delta 3 wire [meaning that one line is grounded], the grounded conductor will become White [or gray if there is a SDS which uses a grounded conductor].Do you mean as on the older 240V delta system with a mid-point ground that was described to me?
If I interpret this correctly, the two hot legs providing normal 120/240V service could be the usual black and red, but the high leg at 208 to ground would have to be orange in this case?
Yes! This is commonly referred to as a "4 wire delta" and is covered in my long winded message above
In a way, it would be a benifit if the Electrons would not flow unless the color code was proper! How many of you guys out there have seen 120 VAC stuff connected to the wild phase? Seen it a bunch of times. All the smoke had left the equipment.
One recent event was at the place my Wife works. They had someone install a 4 plex receptacle on a dedicated circuit to run a Christmas tree flocking machine. After the 4th motor had been fried, they asked me to check it out.
It was a no-brainer; right outside the driveway is the pole with the transformer bank on it. Two small pots on the outside, one large center pot. Secondaries connected in Parallel. Service feeders [Underground] ID labels match on both ends - riser at the pole, plus at the main service.
Mr. Wiggy popped down close to the "240" volt mark when I checked L-N and L-G at the 4 plex receptacle.
Same at the subpanel
So I moved the breaker down one space, filled the hole with a fillerplate painted Orange, went home and printed some "Danger-208 VAC to ground" labels, labeled the subpanels and fixed the "problem"
I charged $50 for this, which was more than it should have been - but they were going to pay $200 and be happy with that! I just felt bad for them having to buy 4 motors and not having a clue to why they burned out so fast.
Heck, I was going to do the work for free! They insisted on paying.