Bus bar stab clearance to wire?


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Old 12-19-17, 05:18 AM
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Bus bar stab clearance to wire?

So I was wondering about this in a small subpanel. Since wires aren't supposed to be bent in an extremely tight loop, and I have more room for a gradual loop with a neutral wire going upward over the neutral bus and down into its lug. This puts it an inch out in front of an unused hot bus stab (the part that a breaker pushes into), which is above the neutral bus. I can zip tie the insulated wire from moving inward toward it, and the wire is quite stiff by itself (it would not move unless forced, and then spring back outward to maintain an inch clearance, and the dead front doesn't touch it, and no other wires are pushing against it).

I tried looking up clearances, or maybe covers for those stabs (which don't seem to exist, other than filler plates that are external to the wiring). So for clearance, people seem to reference only NEC table 408.56: Minimum spacings between bare metal parts, and that says opposite polarity where held in free air is 3/4". Seems okay going by that (and isn't bare metal either). I'd rather not shorten the wire and bend it sharper unless it's really necessary (no plans for a breaker there... although I can see why this question wouldn't usually come up because of that).
 

Last edited by electrialdocius; 12-19-17 at 05:53 AM.
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Old 12-19-17, 05:56 AM
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The only time I have seen conductors physically restrained, apart from the electrical connection itself, has been in motor control centers and large circuit breaker panels where the conductors are larger than 1/0 AND supplying large inductive loads. Mostly large (over fifty horsepower) motor circuits and feeders to the motor control center.

Clearance wise, I wouldn't worry about it if it is as you described.
 
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Old 12-19-17, 06:09 AM
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Yes, the wire is secured exactly one inch out from the bare metal stab, thanks.
 
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Old 12-19-17, 06:35 AM
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If you want more clearance so it does not cross the bus just splice on additional lenght.
 
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Old 12-19-17, 08:26 AM
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I guess it's about the same as hot wires crossing an inch under the neutral bus, or those would have to be expected to touch at times, only separated by a layer of insulation (while wires touching would be separated by two layers). The stab is a bit sharper though.

Well, I ran those around its isolated underbelly (or threw them under the bus, as it were... sometimes that's a good thing).
 

Last edited by electrialdocius; 12-19-17 at 08:59 AM.
 

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