Bonding screw threads at panel stripped

Dsg319 said:
I usually just pick up scrap 12gauge off the floor and ask one of the hvac guys for a sheet metal screw.

Has worked fine for many 1200amp services

Have never had a breaker trip since doing this.

Jk :p
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I hope that was tongue in cheek response. But under those conditions not likely to have it trip a breaker, a large fault would make that #12 a fuse link and probably blow out before the higher 1200A would, or may simply act as if there is no ground and behave as an ungrounded system until you have 2 faults of that 1200A 3ph.
 
Fred B said:
I hope that was tongue in cheek response. But under those conditions not likely to have it trip a breaker, a large fault would make that #12 a fuse link and probably blow out before the higher 1200A would, or may simply act as if there is no ground and behave as an ungrounded system until you have 2 faults of that 1200A 3ph.
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It was , that’s why I said havnt had a breaker trip since I done it lol
 
don_resqcapt19 said:
I will hang a red tag as the on that installation as I do not know that the contact between the outside of the rivet nut to the enclosure wall is suitable for this purpose. That is the only conduct between the enclosure in that installation. I would require the rivet nut to be listed per item 8.
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I'd appeal 250.8(5) covers machine screw-type fasteners that engage not less than two threads or are secured with a nut.
 
Off topic but sense we’re here. How many have you all have went to terminate a larger size say 1/0 EGC to a panel with factory installed mechanical lugs with a small tapped 5/16 head bolt and the lug will spin when tightening the 3/8” hex mechanical lug.
 
@letgomywago posted a interesting photo of what appears to be the aftermath of a Line - cabinet fault in this thread:

Objectionable current question.

In a video demonstration I made i put a load if 67amps in a panel all 67 amps was on one hot and one neutral in the feeder. Then on a branch circuit fed form that panel i made a connection between the neutral and equipment ground at the receptacle. This cause 22 amps of objectionable current...
forums.mikeholt.com
 
petersonra said:
There is NOTHING in the NEC that requires listing unless it specifically states that in the code.
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I know. It still hasn't stopped inspectors in the past from turning down listed items being used for something that doesn't require listing.

I've had insulated staples commonly used for NM cable get turned down when using on AC or MC cable. The insulated staples typically are listed, but AC and MC not mentioned in the instructions. I can use a single piece steel wire type staple that is not listed though, and it is easier to over drive and damage the cable than the plastic ones designed for multiple NM cables.

Same problem in more recent years with those staples listed for multiple cables. Seems sometimes those cables have smaller overall dimension than they did years ago but the staple hasn't changed dimension. Turn down a staple that has wrong combination of cables in it even though they all fit fine where 30 years ago those same cables would been fitting very tight in the staple. All over an item that wasn't required by code to be listed in the first place but since it is listed you supposedly need to follow listing instructions.:sick:
 
Dsg319 said:
Off topic but sense we’re here. How many have you all have went to terminate a larger size say 1/0 EGC to a panel with factory installed mechanical lugs with a small tapped 5/16 head bolt and the lug will spin when tightening the 3/8” hex mechanical lug.
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Happens all the time on Square D size 4 pump panel line terminals with 200 amp fused switch for supply end. Using torque wrench to tighten the conductor connection and the lug itself usually turns. Been that way for years, yet never seen one that has failed either that I can recall.
 
Barbqranch said:
How about a rivet nut? That would give you lots of threads and good contact to the panel.
View attachment 2578432
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So, I have used rivet nuts to "fix" stripped panel cover screws (sometimes all six of them stripped). Would this be a code violation? I'm guessing not since it is not a MBJ. I don't know how you could fix this otherwise. I guess you could tap the holes for larger machine screws, but these would not be the "listed" cover screws with the blunt ends (UL violation?). Let the rocks be thrown.

Mark
 
busman said:
So, I have used rivet nuts to "fix" stripped panel cover screws (sometimes all six of them stripped). Would this be a code violation? I'm guessing not since it is not a MBJ. I don't know how you could fix this otherwise. I guess you could tap the holes for larger machine screws, but these would not be the "listed" cover screws with the blunt ends (UL violation?). Let the rocks be thrown.

Mark
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I'd take a 10/32 rivet nut any day over sharp tip sheet-metal 'tek' screws.
Perhaps its a misprint in my book but 250.8(5) reads to me that machine screw nuts shall be permitted, other than machine' type it does not require any specific type nut.. I imagine machine type is 32 TPI up to #12 screw and 28 TPI in 1/4 in.
 
tortuga said:
I'd take a 10/32 rivet nut any day over sharp tip sheet-metal 'tek' screws.
Perhaps its a misprint in my book but 250.8(5) reads to me that machine screw nuts shall be permitted, other than machine' type it does not require any specific type nut.. I imagine machine type is 32 TPI up to #12 screw and 28 TPI in 1/4 in.
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That type of screw is not permitted.
 
I often encounter those sharp point hex head 'tek' screws used to secure panel covers immediately after the full service 'mechanical' contractor does their HVAC work, its pretty common for those guys to use them to attach ground lugs etc.. I agree they are a violation.
 
don_resqcapt19 said:
That type of screw is not permitted.
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There are self drilling screws out there that tap machine screw threads and of course the threads on those screws are machine type threads.

FWIW pretty much every one of them that I have seen usually is not a practical screw to be using for this sort of thing.
 
Its not about being permitted (well..)
The metal is too skinny for it to not just spin... it also has a thick flange so bonding will be even worse... how about a nice star washer and nut?
 
kwired said:
There are self drilling screws out there that tap machine screw threads and of course the threads on those screws are machine type threads.

FWIW pretty much every one of them that I have seen usually is not a practical screw to be using for this sort of thing.
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That is not the type of screw that was described in the post that I commented on.
 
rambojoe said:
Its not about being permitted (well..)
The metal is too skinny for it to not just spin... it also has a thick flange so bonding will be even worse... how about a nice star washer and nut?
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If you were responding to my last post I was talking about self drilling type screws and not rivet nuts.
 
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