Proper use of a hub

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raider1

raider1

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Logan, Utah
I found this hub installed on a recent permanent power inspection. The hub is installed on the bottom of a meter main combo.



Chris
 
I don't know that it is a violation. I've had underground service changes where the POCO wanted 3" PVC for their wiring, and the panel only came with a bottom hub opening. I installed as in the picture (at least from what I can see). It passed inspection (though I did install an insulated sleeve on the conductors)
 
electricguy61 said:
I don't know that it is a violation. I've had underground service changes where the POCO wanted 3" PVC for their wiring, and the panel only came with a bottom hub opening. I installed as in the picture (at least from what I can see). It passed inspection (though I did install an insulated sleeve on the conductors)
Click to expand...

If you look close at the picture you will notice that the front edge of the KO covers over a portion of the hub opening leaving a sharp metal edge. The overlap was about 3/4" to 1".

The POCO in my area requires a 3" minimum service lateral conduit so hubs of this type are very common.

The problem with this install was the orientation of the hub. If the hub had been installed 180 around then the hub and the knock out opening would have been aligned correctly.

Chris
 
Chris interesting,

Why not use a TA with bushing of course and sched 80 for a lateral and to heck with that mess. Just my thoughts....but then again hind sight is a wonderful thing. I was trying to cite conductors and protection from abrasion previously.:confused:
 
raider1 said:
If you look close at the picture you will notice that the front edge of the KO covers over a portion of the hub opening leaving a sharp metal edge. The overlap was about 3/4" to 1".

The POCO in my area requires a 3" minimum service lateral conduit so hubs of this type are very common.

The problem with this install was the orientation of the hub. If the hub had been installed 180 around then the hub and the knock out opening would have been aligned correctly.

Chris
Click to expand...

I hadn't noticed the alignment. But I 've had inspectors still require the sleeve, so now we just routinely install it
 
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dcspector said:
Chris interesting,

Why not use a TA with bushing of course and sched 80 for a lateral and to heck with that mess. Just my thoughts....but then again hind sight is a wonderful thing. I was trying to cite conductors and protection from abrasion previously.:confused:
Click to expand...

300.5(G) is a good section to cite for this violation.

This install had a metal riser comming up from underground so the hub is cheaper than using a grounding bushing.;)

Chris
 
raider1 said:
300.5(G) is a good section to cite for this violation.

This install had a metal riser comming up from underground so the hub is cheaper than using a grounding bushing.;)

Chris
Click to expand...

Yep Bond bushings can be costly. Would we consider the lateral metallic raceway as needing to be bonded as in 250.92? or am I out in left field? That is not by definition a service. That is Lateral and POCO stuff. just a question.
 
looks like a field modification for sure :smile:,... what's with those screws ?? no nuts ? Did they tap the enclosure
 
dcspector said:
Yep Bond bushings can be costly. Would we consider the lateral metallic raceway as needing to be bonded as in 250.92? or am I out in left field? That is not by definition a service. That is Lateral and POCO stuff. just a question.
Click to expand...

The service lateral riser is part of the service and is supplied and installed by the electrical contractor, so IMHO it needs to be bonded in accordance with 250.92.

Chris
 
M. D. said:
looks like a field modification for sure :smile:,... what's with those screws ?? no nuts ? Did they tap the enclosure
Click to expand...

The enclosure had factory tapped holes for 1/4 20 bolts, but the installer choose to use their own rather long bolts then the fatory supplied ones.:)

Chris
 
raider1 said:
The service lateral riser is part of the service and is supplied and installed by the electrical contractor, so IMHO it needs to be bonded in accordance with 250.92.

Chris
Click to expand...

Just slide a lug over one of those screws followed by a nut:D
 
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