Bonding Conduits

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It is interesting to note that if you buy a UL approved grounding bushing made by Crouse Hinds it only comes with a lug rated up to 1/0 nothing larger.
If you change this lug to a 3/0 one to accept the so called 3/0 required by the code then you have voided the UL listing on the grounding bushing.

First off you cannot "void" a listing. The part is listed regardless of what you do to it. You might install it in a manner inconsistent with the manufacturer's instructions, but the part is still listed.

Do you know for a fact that CH prohibits one from changing the lug to a different size? Just because they supply it with a certain size lug on it does not mean you can't change it, just like you can change lugs on circuit breakers. There is no general rule that prohibits one from changing lugs on devices, whether they are listed or not.
 
How does a person find out if you can change the lug? Also if you change the lug have you still installed the part according to the manufactures directions?
What I have found is sometimes the larger lug is too large to fit on the bushing. What I mean is, the hole for the screw that attaches the lug to the bushing is in the center. There for the back end of the lug is touching the box and the screw doesn't line up with the threaded hole. What I do for that is hold the lug with channel locks and hack saw some of the lug so the hole does line up.
Thanks
Mike
 
How does a person find out if you can change the lug? Also if you change the lug have you still installed the part according to the manufactures directions?
What I have found is sometimes the larger lug is too large to fit on the bushing. What I mean is, the hole for the screw that attaches the lug to the bushing is in the center. There for the back end of the lug is touching the box and the screw doesn't line up with the threaded hole. What I do for that is hold the lug with channel locks and hack saw some of the lug so the hole does line up.
Thanks
Mike
I am pretty sure this would be considered an inappropriate modification.
 
Probably so... but finding one that does will certainly alter an otherwise great day.

FWIW, I have seen metal connectors with locknuts that are UL listed, but not to UL 514B, so be cautious.

Are you referring to the flexible type mentioned here under cat. code DWTT? according to this, your typical EMT fitting is ok, no restrictions.

[h=4]GROUNDING[/h]All metal fittings for metal cable, conduit and tubing are considered suitable for grounding for use in circuits over and under 250 V and where installed in accordance with the NEC, except as noted for flexible metal conduit fittings and liquid-tight flexible metal conduit fittings.
 
I know that is required by UL when reducing washers are incorporated:
The following information comes from UL 514B;
8.34 Reducing washers resistance test
8.34.1 ? reducing washers shall be assembled to threaded conduit and unpainted steel plates as illustrated in Figure 16, and then subjected to the resistance test described in Clause 8.9. As a result of the test, the voltage drop shall not be greater than 10 millivolts. The samples shall then comply with the current test described in Clause 8.10.

I was not aware it was required on standard locknuts.

To take it one step further, cat. code QCRV states that reducing washers are listed for grounding when installed per NEC. It is not mentioned, but (assumed?) the installer will remove paint.
Maybe it's in the installation instructions, but who publishes those for reducing washers? (sarcasm)
Is it assumed the user will remove paint for locknuts also?
If you compare statements in DWTT and QCRV under grounding neither tell you to remove paint. The standards tell the manufacturer how to pass the test for reducing washers, but are generally unavailable to the public, like the guide info is.

Even cat. code KDER has no help. It talks of grounding locknuts, but those are ones with a set screw. You EMT connector has probably not been investigated with that particular locknut.
Cat. code DWTT does have a blanket statement that: All male threaded fittings and nipples have only been investigated for use with locknuts.
Maybe that means any locknut

a search on the entire UL website yields no hits for "remove paint" that pertains to locknuts or conduit fittings.

Only one product guide info that I could find has any mention about paint and that is Victaulic couplings. "The pipe is to be grooved or rolled in accordance with the manufacturer's installation instructions. Couplings are protected by galvanized coating or may be painted." File: KDER.EX1820

So looks to be up to local AHJ unless more info is forthcoming from UL

To access what I referenced use this link:
http://database.ul.com/cgi-bin/XYV/template/LISEXT/1FRAME/index.html
 
It is interesting to note that if you buy a UL approved grounding bushing made by Crouse Hinds it only comes with a lug rated up to 1/0 nothing larger.
If you change this lug to a 3/0 one to accept the so called 3/0 required by the code then you have voided the UL listing on the grounding bushing.
Guess maybe the code allows you to clip off a few strands to fit the lug.
It would be nice if everyone would get their act together and make products that comply.
And it is certainly be difficult to bend 3/0 cable into lugs that are about five inches apart. Kind of silly to expect that you will have good solid contact at the lug.
A #14 wire will explode at about 400 amps dead short. A 3/0 is probably around 9000 amps or more. If your overcurrent device with ground fault and instantaneous trip doesn't go by then, it would be kiss your equipment goodbye anyway.

Here's a pdf for crouse hinds with lugs up to 250 MCM for 3'

http://www.cooperindustries.com/con...-products/catalog-pdfs/grounding-bushings.pdf
 
Are you referring to the flexible type mentioned here under cat. code DWTT? according to this, your typical EMT fitting is ok, no restrictions.

GROUNDING

All metal fittings for metal cable, conduit and tubing are considered suitable for grounding for use in circuits over and under 250 V and where installed in accordance with the NEC, except as noted for flexible metal conduit fittings and liquid-tight flexible metal conduit fittings.
No. According to this, these suitable for grounding fittings must be as highlighted above. NEC requires paint removal where fitting is not designed so you don't have to. Nothing in the category differentiates between one that does and one that doesn't. That's why I said be cautious.
 
I am pretty sure this would be considered an inappropriate modification.

I was more than aware of that but what are you supposed to do? The lug will not turn so you can get a wire through it. I have made some work by putting a lock nut on first or doubling a lock nut once or twice.
Thanks
Mike
 
No. According to this, these suitable for grounding fittings must be as highlighted above. NEC requires paint removal where fitting is not designed so you don't have to. Nothing in the category differentiates between one that does and one that doesn't. That's why I said be cautious.

I should have asked before, which connectors have locknuts that do not pass 514B
 
I should have asked before, which connectors have locknuts that do not pass 514B
I do not recall any specific ones at present. Also take into consideration I have over 30 years of experience, and products do change over time. I'd say the majority currently on the market are listed to 514B. Additionally, current internet-posted information does not always indicate full listing information. It's much easier to look at the locknuts and determine if they are made to gouge through paint. So I'm not going to do exhaustive research just trying to find one that is not listed to 514B. If you have an insatiable need to find one, please feel more than welcome to do so yourself... :happyyes:
 
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