Tapping inside a service switch with polaris connectors

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Tainted said:
Well, there is a knockout in the disconnect switch. It was designed for that specific purpose. I have to disagree with you respectfully
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And there is a nut on a stud that is made to hold a lug, switching lugs doesn't change that purpose. Lots of equipment comes without lugs and you install your own. Listed just means it's built to a standard.
 
ActionDave said:
And there is a nut on a stud that is made to hold a lug, switching lugs doesn't change that purpose. Lots of equipment comes without lugs and you install your own. Listed just means it's built to a standard.
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I can make the argument that changing the lugs could probably affect the equipment during a fault. One loose nut can cause the disconnect switch to fail during a fault, won't it? The manufacturer might have tightened the nut that holds the lugs in a certain way to mitigate the event of a fault. In my opinion, the liability transfers over to the installer once the lugs are changed and modified..
 
Tainted said:
I can make the argument that changing the lugs could probably affect the equipment during a fault. One loose nut can cause the disconnect switch to fail during a fault, won't it? The manufacturer might have tightened the nut that holds the lugs in a certain way to mitigate the event of a fault. In my opinion, the liability transfers over to the installer once the lugs are changed and modified..
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Would you insist that the entire disconnect be replaced if someone loosened and re-tightened a nut? :unsure:
 
I know of a case where an electrician field modified a 480/277V panel that came with single lugs to wire it with three parallel sets of conductors. Two of the replacement lug ports were side by side instead of stacked and the outer one on one of the lines was very close to the grounded support rail inside the enclosure. The weather got hot and the wiring heated up from the current passing though it; the metal all expanded, and you can guess what happened. It's a lucky thing no one was close to the panel when it blew up.
 
ActionDave said:
And there is a nut on a stud that is made to hold a lug, switching lugs doesn't change that purpose. Lots of equipment comes without lugs and you install your own. Listed just means it's built to a standard.
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Right, we change lugs all the time. Some equipment I use doesnt even come with lugs. Sometimes I bolt on a mechanical lug, sometimes I use crimp on lugs. To call changing lugs a "listing violation" is ridiculous. As an example, I often buy my CT mounting bases with just studs, no lugs. The have 2 studs with NEMA standard centers. You use whatever lug fits the wire you use and the crimp tooling you have. That is why there are industry standard bolt centers.
 
electrofelon said:
Right, we change lugs all the time.
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When swapping in larger lugs, what NEC section or UL standard do you reference to check whether the remaining clear space between energized lugs, or between lugs and grounded metal, or lugs and insulators, is still sufficient? Just thinking about ggunn's example.

Cheers, Wayne
 
wwhitney said:
When swapping in larger lugs, what NEC section or UL standard do you reference to check whether the remaining clear space between energized lugs, or between lugs and grounded metal, or lugs and insulators, is still sufficient? Just thinking about ggunn's example.

Cheers, Wayne
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I am not aware of anything in the NEC applying. I have not dug into whether there is a product standard that provides specifics on clearances between connectors. I guess my argument is that as a professional, I need to makes judgments in the field all the time, such as clearances between conductors and sharp edges, conductor routing in vibrating thing like generators and motors, mechanical strength of cabinet and conduit supports, and the list goes on and on.
 
FWIW, for panelboards UL 67 Section 16 and Table 16.1 specify the required spacings. For example, for uninsulated parts separated by air, at 125V or less 1/2" is required between live and live or live and case. For 250V it's 3/4" and 1/2", respectively, and then for 251V-1000V it's 1" and 1".

There's also a column in Table 16.1 for "over surface" which I'm not 100% clear on the applicability of. I think it covers the case where you separate two lugs with an insulating barrier and then measure the distance around the barrier. Those numbers are 3/4", 1-1/4", and 2", respectively, for the 3 voltage levels I mentioned.

Cheers, Wayne
 
wwhitney said:
FWIW, for panelboards UL 67 Section 16 and Table 16.1 specify the required spacings. For example, for uninsulated parts separated by air, at 125V or less 1/2" is required between live and live or live and case. For 250V it's 3/4" and 1/2", respectively, and then for 251V-1000V it's 1" and 1".

There's also a column in Table 16.1 for "over surface" which I'm not 100% clear on the applicability of. I think it covers the case where you separate two lugs with an insulating barrier and then measure the distance around the barrier. Those numbers are 3/4", 1-1/4", and 2", respectively, for the 3 voltage levels I mentioned.

Cheers, Wayne
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Would not 366.100 E be your guide...if your modifications comply with dimensions listed here you should be fine.
 
Just thinking out loud...

If you really really did not want to swap out those single lugs for fear of a listing violation, could you keep the original lugs and use a pin adapter?

Something like this...
1674265321274.png
 
Tainted said:
Never thought about this… i never knew about this product lol
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They make all kinds of crazy pin adapters. The most common is a crimp style to reduce the wire size for fitting into a terminal that's too small. But there are all kinds of others.

Also, Hillbilly1 mentioned a large Polaris that can fit over the wire. With something like the image below you could also fit it over the existing wires and give yourself another port to tap off from. With this "split case" insulation piercing type, you might not even have to ever remove the exisiting wires from the lugs.

1674314834147.png

It's like a nicer version of an old fashioned split bolt clamp.

The above is an Ilsco IPC-4/0-6 4/0-6. I have no idea of your wire sizes and am, just again, thinking out loud.

Apologies in advance if you already know about these.

Good luck.
 
My opinion is that the best solution for modifying an existing installation is usually to do what one would have done as a new installation. In this case, it would have been either type of double lug.

1674316854207.png 1674316918673.png
 
ActionDave said:
Makes sense to me.
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I do that once in a while. :sneaky:

I like my work to look like I did it that way on purpose, rather than like I had to adapt and modify.

An example is replacing a 1g box with a 2g for an added switch instead of adding a second 1g box.
 
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My experiences with this is quite often it gets crowded pretty fast when you add that second set of conductors.

Then there have been times where I might parallel conductors because of long distance and of course is still crowded in there.

An add on situation often might just change the lugs like many have mentioned.

A new install when known there will be two sets of conductors to terminate - probably adding a splice box instead of trying to jam everything into the disconnect. There is some "terminal boxes" out there that have pre installed multiport terminal bars in them. Those are often similar or even less price than your own box with Polaris type connectors in it. for a 200 amp version you likely only making 2 200 amp taps to it though they will have like three other smaller ports in the block that will handle maybe up to about #2 - 1/0 conductor.
 
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