Fitting used for choking ground

[lewis3180]

Does anybody know what the fitting is called to bond the grounding conductor to emt? I've heard it called choking ground. I can't seem to find a fitting anywhere. Does anybody know a manufacturer or name for the fitting??

 

[hbiss]

Re: Fitting used for choking ground

If you look hard there is one that will thread on the end of RMC but I doubt many supply houses will carry it. Most guys just use a romex to EMT connector.

-Hal

 

[al hildenbrand]

Re: Fitting used for choking ground

This is an interesting question. I paused after my first thought. In my area, I see a lot of service entrances assembled in EMT. Occasionally, the EMT between the meter socket and the service center (disconnect) will be bonded with a plain old ground clamp.

Then I thought, "These are water pipe ground clamps. . .is that a limitation?"

I'm starting to look it up.

 

[al hildenbrand]

Re: Fitting used for choking ground

From the UL White Book

GROUNDING AND BONDING EQUIPMENT (KDER)
Use.
Ground Clamps ? Strap type ground clamps are not suitable for attachment of the grounding conductor of an interior wiring system to a grounding electrode.

Ground clamps and other connectors suitable for use where buried in earth or embedded in concrete are marked for such use. The marking may be abbreviated ??DB?? (for ??Direct Burial??).

Listed ground clamps are also suitable for telecommunication applications such as telephone, radio, CATV, and the like in accordance with Articles 800, 810, 820 and Section 250.94 of the NEC, in addition to those covered under Grounding and Bonding Equipment, Communication (KDSH).

Listed irreversible compression type connectors are suitable for splicing the grounding electrode conductor.

Clamps are intended for use with rod and/or pipe electrodes in accordance with the NEC and are marked with the size of electrode and electrode grounding conductor with which the clamp is intended to be used. Clamps suitable for use on copper water tubing are marked for such use.

[ September 19, 2005, 01:59 PM: Message edited by: al hildenbrand ]

 

[infinity]

Re: Fitting used for choking ground

Most guys just use a romex to EMT connector

Are these fittings listed for bonding? I think that a better solution would be an EMT connector and a threaded grounding hub that is designed to bond the grounding conductor to the conduit.

 

[roger]

Re: Fitting used for choking ground

We call them city hubs, why, I don't know.

We use these on a regular basis, here is a recent case.

Roger

[ September 19, 2005, 06:18 PM: Message edited by: roger ]

 

[stud696981]

Re: Fitting used for choking ground

Roger,

Your pic is a very neat install!

In regards to using a romex to emt connector, they are not listed for this purpose. I have seen them used before, but an inspector could reject them since they are not listed for bonding a GEC.

 

[infinity]

Re: Fitting used for choking ground

Roger,

Neat job but I'm curious as to why you wouldn't connect the conduit directly to the grounding bus using the hole provided in the "city hub" and save on the additional lugs?

 

[roger]

Re: Fitting used for choking ground

Stud and Infinity thanks for the compliment, but it was not me that did this work, it was a very good crew, you can see more of the installation here .

Infinity, I have actually done that before, but believe it or not can be more aggravation to do it that way. This job for instance was where certain transformers would be brought online months before another was, and the GEC's for each was landed some time apart. The easiest solution to not get in your own way is to keep the congestion on the bar as minimal as possible.

The bar per the specs is for future connections also. (I don't know how though, the room is packed)

In the cases where we purchase predrilled bars (not in this installation) it normally doesn't work out either.

Other than that there is nothing wrong with doing it.

Roger

 

[na112233]

Re: Fitting used for choking ground

I call it a choke fitting----see Roger"s drawing. OZ Gedney makes them but I don't have a part number