Meyers Hubs and Grounding

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VectorAndy

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We are currently working on a project wiring the Heat and Ventilation system for a new scrubber system at a local coal-fired power plant. We are having an argument with the QC inspector regarding grounding of the conduit system with meyers hubs. According to the UL White Book the meyers hubs we are using are listed for grounding.

The main contractor's crews are taking the manufacturer's locking ring off the hubs, replacing them with standard locknuts, and putting a bonding bushing on the myers hub. This seems like a violation of the UL listing to me.

These are 480V and 120V systems, we are pulling a ground conductor in each conduit for grounding of the equipment. I feel like we are complying with 250.97, and our raceway system is properly bonded.

Am I wrong with my thinking, or can someone give me some ammunition to throw at the QC man?
 
don_resqcapt19

don_resqcapt19

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Location
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retired electrician
The QC inspector may be enforcing the job specs which may call for a bonding jumper. That is often the case for powerhouse and industrial work. If that is the case, you just need to get the hubs that are designed for use with a bonding jumper.
 
chris kennedy

chris kennedy

Senior Member
Location
Miami Fla.
Occupation
60 yr old tool twisting electrician
don_resqcapt19 said:
get the hubs that are designed for use with a bonding jumper.
Click to expand...
I've never seen nor heard of these. This is not the first time this issue has come up here.

Got a quick link or do I have to Google?;)
 
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VectorAndy

Member
don_resqcapt19 said:
The QC inspector may be enforcing the job specs which may call for a bonding jumper. That is often the case for powerhouse and industrial work. If that is the case, you just need to get the hubs that are designed for use with a bonding jumper.
Click to expand...

We are trying to figure out if this is the case here. The written specs don't call for it, but there is the ubiqitous phase of "unless otherwise noted on design drawings". There's nothing in the bid set that I received for the HVAC subsystem, but who knows what drawings might be floating around out there on a project this size.

Our biggest issue is that QC didn't pick up on this for the first two buildings we completed, and we have pulled wire through most of these fittings, so we either get bonding wedges to slide in there, or we determinate, and change the standard hub locknut to the bonding type.

I'm still of the mind that what Shaw is doing with replacing the hub locknut with a standard locknut and a bonding bushing is voiding the UL listing.

Oh well, that's the contracting business. I appreciate the advice, and I look forward to spending some more time on the forum.

Andy McClure
Vector Electric
 
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