bonding bushing on LB

Z

Zee

Senior Member
Location
CA
Settle a disagreement for us:
an electrical sub (I am a solar guy) says he doesnt need a grounding/bonding bushing on a metal LB that enters a PVC box. The LB penetrates the stucco wall at its other port. From there Rx runs through the basement.
I don't see why not, it is a metal raceway into a non-conductive box.
 
electrofelon said:
Is he saying the metal LB can be left floating and un bonded, or is there some debate whether the LB IS bonded or that bonding is acceptable? If the former, have him look at 250.4 (A).
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Here's the applicable wording

(3) Bonding of Electrical Equipment. Normally non–
current-carrying conductive materials enclosing electrical
conductors or equipment, or forming part of such equipment,
shall be connected together and to the electrical supply
source in a manner that establishes an effective groundfault
current path.
 
electrofelon said:
Is he saying the metal LB can be left floating and un bonded, or is there some debate whether the LB IS bonded or that bonding is acceptable? If the former, have him look at 250.4 (A).
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Not sure what he's saying .... I got the message relayed through my employee. He says it's Romex and so doesn't need a grounding bushing......
but he installed an LB on that Rx into our PVC box and didn't put grounding bushings on it.
You know what ....he's probably just reflexively accustomed to running Romex in a crawlspace, putting an LB on it outside, and going right into a metal can.... and in that case he wouldn't need a grounding bushing.
 
Zee said:
Not sure what he's saying .... I got the message relayed through my employee. He says it's Romex and so doesn't need a grounding bushing......
but he installed an LB on that Rx into our PVC box and didn't put grounding bushings on it.
You know what ....he's probably just reflexively accustomed to running Romex in a crawlspace, putting an LB on it outside, and going right into a metal can.... and in that case he wouldn't need a grounding bushing.
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This recently came up in another thread (if this is what he is claiming/thinking): some people throw in the "likely to be energized" phrase and will claim something isn't likely to become energized and thus doesn't need bonding. Note the section in 250.4 does not use the phrase "likely to become energized" so there is no way to avoid the bonding.
 
To my knowledge the only exception to bonding metal portions of raceways is rigid 90’s underground in pvc raceways.

I’ll have to look it up but I don’t even think that exception applies if the raceway is above ground. But a greater mind than mine will no doubt confirm or deny that.
 
Seven-Delta-FortyOne said:
To my knowledge the only exception to bonding metal portions of raceways is rigid 90’s underground in pvc raceways.

I’ll have to look it up but I don’t even think that exception applies if the raceway is above ground. But a greater mind than mine will no doubt confirm or deny that.
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And I believe that exception was recently expanded a bit to apply to straight runs and not just elbows.
 
The proper way to do this, is to install a close nipple on one of the hubs, and terminate it with a bonding bushing. Either that, or a long enough nipple that you can attach a U-bolt grounding clamp externally.

It's not possible to put a bonding bushing on threaded female entries anyway, and there's no built-in provisions for attaching a bonding lug to an L-body, and it'd violate the product listing to install your own. This is why the rule about fastening upsized conduit bodies is so out-of-touch with reality, since there's no mounting provisions on conduit bodies.
 
Carultch said:
and there's no built-in provisions for attaching a bonding lug to an L-body, and it'd violate the product listing to install your own
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This I doubt. You can drill a weep hole if you want, and you could drill and tap for a grounding lug if you want.

Cheers, Wayne
 
Carultch said:
it'd violate the product listing to install your own.
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There is no such thing as "violating a listing". There is "manufacturer instructions" in 110.3(B) and to violate that section the instructions for the lb would have to specifically say you cannot drill holes and/or mount lugs in it. An AHJ could deem it not acceptable per 110.2, but without do anything contrary to the instructions, and considering drilling and tapping and bolting grounding lugs onto enclosures is extremely common, I would find that quite unreasonable.
 
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