Something still surprise me

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jwelectric

Senior Member
Location
North Carolina
110.15 High-Leg Marking.
On a 4-wire, delta-connected system where the midpoint of one phase winding is grounded, only the conductor or busbar having the higher phase voltage to ground shall be durably and permanently marked by an outer finish that is orange in color or by other effective means. Such identification shall be placed at each point on the system where a connection is made if the grounded conductor is also present.

What if it is a 120/240 delta ststem is supplied from a 480 volt transforner installed in the same building?
Could the 480 system still have BOY color coding if it was a wye system?
 

rlMutch

Senior Member
Location
WA state
Wow, this thread really morphed into something interesting!

jwelectric said:
What if it is a 120/240 delta ststem is supplied from a 480 volt transforner installed in the same building?
Could the 480 system still have BOY color coding if it was a wye system?
I suppose, if you had a 120/240 delta system in the same facility with a 480/277 system, you would have to specify a color code (according to 210.5(C)) for the 480/277 system ungrounded conductors with some color other than orange????

Maybe this deserves it's own thread.
 

bstoin

Senior Member
For 277/408 I have always seen and used Brown, Purple, Yellow (just remember alphabetical order...BPY.)
 

jwelectric

Senior Member
Location
North Carolina
For a premises that is supplied with 480/277 with a 208/120 and a 240/120 system I use a simple marking system.
Black is one
Blue is one
Red is one
If the person coming in behind me can?t afford a phase rotation meter then let him guess.
 

acrwc10

Master Code Professional
Location
CA
Occupation
Building inspector
rlMutch said:
OK, I'll bite... So what is the correct color code for 480/277 phase conductors according to the NEC???;)


No reason to bite :D I see the BRN-ORN-YEL as 277/480 why change from what is an "unofficial" standard. If purple yellow and red are your local standard why change it ?
 

acrwc10

Master Code Professional
Location
CA
Occupation
Building inspector
jwelectric said:
For a premises that is supplied with 480/277 with a 208/120 and a 240/120 system I use a simple marking system.
Black is one
Blue is one
Red is one
If the person coming in behind me can?t afford a phase rotation meter then let him guess.

If he is really cheap he could also use two fingers as a volt meter. Only thing you need is some one to revive him once in a while :grin:
 

jmd445

Senior Member
In lieu of the emt you need to look at it from a plumbers perspective.......... 'L' copper for high current protection, 'M' copper for lower current protection. If really desperate you wrap tin foil around pvc pipe.

Jim
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Mike,
What if it is a 120/240 delta ststem is supplied from a 480 volt transforner installed in the same building?
Could the 480 system still have BOY color coding if it was a wye system?
If the high leg is orange, then the use of orange for the the 480 volt system conductors is prohibited by 210.5(C).
Don
 

dcspector

Senior Member
Location
Burke, Virginia
Phase taping is a Local thing. DC requires 208/120 Blk. Red, Blue, white and 480/277 B.O.Y, grey. I have a feeling it will be in the NEC one of these code cycles.
 
don_resqcapt19 said:
Mike,

If the high leg is orange, then the use of orange for the the 480 volt system conductors is prohibited by 210.5(C).
Don
Only by the severest interpretation, and I have never found [not saying it doesn't happen] a 240 delta in a building with 277/480 ... I have always found the second system to be a 120/208 Y for receptacles, as the lighting is commonly fed from the 277 and mechanical equipment with the 480.
With the availability of 277/480 and the improvements in 208 equipment, it is likely the 240 delta will go the way of 2-phase ...
 
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raider1

Senior Member
Staff member
Location
Logan, Utah
Only by the severest interpretation, and I have never found [not saying it doesn't happen] a 240 delta in a building with 277/480 ...

I have been involved with projects that have a 480/277 volt and 240/120 volt delta systems. I agree that they aren't very common but they do occur.

With the availability of 277/480 and the improvements in 208 equipment, it is likely the 240 delta will go the way of 2-phase ...

The local utility in my area won't provide a 3 phase 240/120 volt delta system on a new building any more unless you get special permission from them.

Chris
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
two systems

two systems

" have been involved with projects that have a 480/277 volt and 240/120 volt delta systems. I agree that they aren't very common but they do occur."

This arrangement was common enough in one area I've worked that the local AHJ requested that 480 systems use Brown-Purple-Yellow as a standard and use Orange only for 240 Hi-Leg systems
 

iwire

Moderator
Staff member
Location
Massachusetts
brian john said:
Electricians that change colors in the middle of a job, because of some mis-guided belief that the NEC requires what ever they believe, cause more problems than necessary.

I agree.
 

iwire

Moderator
Staff member
Location
Massachusetts
jwelectric said:
For a premises that is supplied with 480/277 with a 208/120 and a 240/120 system I use a simple marking system.
Black is one
Blue is one
Red is one

Enjoy this for the three years it will be allowed.:cool:

It was a violation under the 2002 for MWBCs and looks like it will be a violation for all circuits under the 2008.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Greg,
Phase taping is a Local thing. DC requires 208/120 Blk. Red, Blue, white and 480/277 B.O.Y, grey. I have a feeling it will be in the NEC one of these code cycles.
There was a requirement for the use of specific colors a number of code cycles ago, but I doubt that it will ever return. The color used for the identification of the phase and system is a design issue and not a code issue.
Don
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Robert,
Only by the severest interpretation,
Why do you say that? The conductors must be identified by system, if there is more than one voltage system in the building, under the rule in 210.5 as found in the 2005 code. If you use orange for the high leg and for the B phase of the 480/277 volt wye system, how have you identified between the two systems?
Note that an expected change to 210.5 for the 2008 code will require that the ungrounded conductors of multiple systems be identified as to both system and phase. There is no code requirement to have differing grounded conductor identification unless the grounded conductors from more than one system are found in the same raceway or enclosure.
Don
 
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