WHY?? One leg red in 240AC Circuit

I remember back in the day when I did electrical work...
The "red" leg was identified with red or orange tape at the circuit breaker panel..
when needing 120 VAC you had to be careful not to use the 'red leg'
I never used the 208 to ground to run anything...
 
I remember back in the day when I did electrical work...
The "red" leg was identified with red or orange tape at the circuit breaker panel..
when needing 120 VAC you had to be careful not to use the 'red leg'
I never used the 208 to ground to run anything...

Yes, me too. That's 240 V 3 phase center tap delta. The red or orange tape is denoting the "wild" or "high" leg of the 3 phases. It runs around 190 Volts, 240 phase-to-phase. When something gets fried by a new electrician using this voltage in a panel, it's easy to spot: Breaker-breaker-space. Breaker-breaker-space. Breaker-breaker-NEW breaker. Ka-boom. There goes the smoke.
 
That is an oddball panel, but he is incorrect about High Leg Delta being "banned by the NEC". Totally wrong there, it's still available and is in fact very common in some areas.
Just ran into one the other day. Open delta used as single phase 120/240 with wild leg capped. Pretty cool that you could used 3 phase 240 if you needed. Seems commercial and light industrial still use it, as POCOs like it since they can use just 2 pole mounted transformers.
 
Open Delta with "Stinger" Leg are quite common in San Francisco

Especially in older buildings

New code book says the stinger leg must be phase "C" and Purple in color
.Black, Red, Purple

Most older installations I see the stinger leg is "B" and Orange in color
.Black, Orange, Purple

San Francisco has it own electrical code book that says
"This Electrical code supersedes all other electrical codes & ordinances
in the City and County of San Francisco"

High-Leg = Wild-Leg = Bast*rd Leg = Orange Leg = Stinger leg & even Red-Leg

Our newer code book refers to it as High-Leg
and actually has "Orange" struck out and replaced with Purple

Orange is now only allowed for 277/480
Brown, Orange, Yellow
 
If discussing PLCs and such, we are always discussing industrial applications.


The Black/Red on 240V circuits is applicable to residential wiring. It has no meaning or validity in industrial systems. Black/Red for 240V single phase systems would be confusing and potentially dangerous for industrial systems.



In control panels, black = Line Power, red = AC control power, white = Neutral, blue = DC control power, yellow = Foreign source control power that is not disconnected by the main disconnect. These standards go back to the original JIC (Joint Industrial Council) standards from around WWII that eventually became absorbed by NFPA 79 for industrial machinery electrical systems. The standards were established to help prevent accidents when workers moved between facilities that might have had different standards. So when an industrial electrician opens a panel to try to troubleshoot a problem, he knows what he is looking at without needing a color chart.

Just want to point out that Yellow is no longer the foreign source color. It was replaced with orange.
 
Just want to point out that Yellow is no longer the foreign source color. It was replaced with orange.
We are both right (or both wrong, depending on your point of view).


14.2.4 Identification by Color for Other Conductors.
14.2.4.1* Ungrounded circuit conductors that remain energized
when the supply disconnecting means is in the off
position shall be consistently applied as either ORANGE or
YELLOW. These color identifications shall be strictly reserved
for this application only.
 
NFPA 79 2018

13.2.4.1 The color ORANGE shall be used to identify ungrounded conductors that remain energized when the main supply circuit disconnecting means is in the off position. This color identification shall be strictly reserved for this application only.
 

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