3 phase buses have a requirement that a High-Leg be terminated on "B" Phase {408.3(E)}. Is there any requirement on teminating a High=leg conductor in a fusible disconect. If so, what Code reference ?
"High-Leg" Orientation
- Thread starter augie47
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hillbilly1
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- North Georgia mountains
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- Owner/electrical contractor
I would think it would be the same, the reasoning being, it always is the center phase when looking at a gear from the front or back. If your moving it to correct rotation on a motor, I would move A and C, and leave B alone.
Oh how great it would be if my inspector role involved reasoning
I agree with you, but when the contrcator asks for a Code refernece, "reasoning" won't cut it 
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- Semi-Retired Electrician
I don't know of any code language saying anything about high leg marking on fused disconnects. Although it usually is common sense to mark the high leg on all equipment, I think the reason the NEC doesn't address this is you wouldn't normally pull a 120V circuit off a 3-ph disconnect. I also believe that the rule covering marking the panel boards, switch gear, etc. for a high leg is for when a 120V circuit might be pulled from them. I have nothing but my opinion to back this up.
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- Electrical Engineer
Your opinion and again, common sense...
The only places in the NEC where orientation of the high leg is mentioned is in 408.3 (E) and 409.102, both of which are specific to busbars, no mention of equipment like disconnect switches. The high leg conductor must be marked as orange, that is consistent everywhere, but not which phase it is unless it is related to bus bars. "Conventional wisdom" however would say that if it is B phase in the gear that has bus, it should be B phase everywhere else in order to maintain consistency. I would/did.
"Consistency" and common sense are however not actually NEC requirements...
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- Wisconsin
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- PE (Retired) - Power Systems
I agree, the NEC does require the 'high-leg' to be identified everywhere. For insulated conductors the general requirement is that they be colored orange, or identified in another manner. For uninsulated conductors, which are typically bus bars, the identification is done by location of the bar in the center or B position.
hillbilly1
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- North Georgia mountains
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I had a big city inspector turn me down on a new service I installed, the old service was a full delta 120/240, new service was 277/480. Normally the standard around here is Brown,Orange and Yellow, but since I installed a delta transformer to power the existing panels, I used Yellow, Brown and Purple. (For the 480 volt service) He would not pass me until I changed the Purple to Orange. He kept saying nobody would know what the Yellow, Brown and Purple was for. I argued that the high leg MUST be orange, so I could not use orange for the other system, but to no avail. Changed it back after he left! LOL!
drcampbell
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Nor would anybody hesitate to pull out a voltmeter and check when encountering something out of the ordinary.
Consistency & common sense are not requirements in a wide variety of contexts. It's hardly limited to just the NEC.
Which is a hesitation I'd have to take if I came across something phased Brown, Purple, Yellow.
Brown, Orange, Yellow not so much.
JAP>
@augie47 What we commonly call a 'fused disconnect' is not a defined term in the NEC that I know of. There is a definition of 'switchgear' which 408.3(E) applies to.
"Switchgear. An assembly completely enclosed on all sides and
top with sheet metal (except for ventilating openings and inspec-
tion windows) and containing primary power circuit switching,
interrupting devices, or both, with buses and connections."
"Switchgear. An assembly completely enclosed on all sides and
top with sheet metal (except for ventilating openings and inspec-
tion windows) and containing primary power circuit switching,
interrupting devices, or both, with buses and connections."
hillbilly1
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- North Georgia mountains
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- Owner/electrical contractor
If I had left it, I would have been in violation of code, you cannot use the same color to identify two different systems. And yes, BOY has been used for decades, but YBP was the accepted standard before that. I think it still is in Texas.
The reasoning behind the change, is in a dark ceiling, brown and purple is hard to distinguish, hence the change.
I would of pondered that code requirement for about a half second and with an inspector beside me who felt the same as I on color coding would have phased the 489v BOY from the beginning and left it.
Good to hear there's still a few outlaw inspectors out there who don't sweat the small stuff.
Jap>
Good to hear there's still a few outlaw inspectors out there who don't sweat the small stuff.
Jap>
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- Illinois
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- retired electrician
It is covered by Article 404 and is called a "fused switch" in that article.
lkdiaZ
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404.27 references fused switches. Does it follow then that a disconnect switch whether fused or unfused falls under the category of a knife switch as referenced starting in 404.6(A)?
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- Illinois
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- retired electrician
Only if it is of the knife switch design. There are other designs used for disconnect switches.
I ask you all to consider how is a fused disconnect not
" An assembly completely enclosed on all sides and
top with sheet metal and containing primary power circuit switching,
interrupting devices, or both, with buses and connections."?
@augie47 inspected it and thinks the B phase should be Orange, I am trying to back him up here with a legal argument.
Article 404 addresses a "fused switch", a subset of switchgear.
If the CMP wanted to distinguish switchgear and "fused switches" from each other they would have a definition in art 100 for 'fused switch'.
Both 408 and 404 apply to the "fused switch" in this case as there is no relief from the definition of switchgear in Art 100.
Article 408 need not include 'fused switches' if they are alredy included by the broad definition of switchgear.
While I generally think of a 'cabinet' as something I put my coffee in and no more, the NEC definitions are quite old and demand careful consideration like a Venn diagram.
Cheers
" An assembly completely enclosed on all sides and
top with sheet metal and containing primary power circuit switching,
interrupting devices, or both, with buses and connections."?
@augie47 inspected it and thinks the B phase should be Orange, I am trying to back him up here with a legal argument.
Ahh Yes but with all due respect I maintain article 404 does not modify 408 or the definition of switchgear in article 100.
Article 404 addresses a "fused switch", a subset of switchgear.
If the CMP wanted to distinguish switchgear and "fused switches" from each other they would have a definition in art 100 for 'fused switch'.
Both 408 and 404 apply to the "fused switch" in this case as there is no relief from the definition of switchgear in Art 100.
Article 408 need not include 'fused switches' if they are alredy included by the broad definition of switchgear.
While I generally think of a 'cabinet' as something I put my coffee in and no more, the NEC definitions are quite old and demand careful consideration like a Venn diagram.
Cheers
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