Two conductors under one CB terminal

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Nigeno

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Found similar threads:
https://forums.mikeholt.com/threads/multiple-wires-on-each-lug-of-a-panelboard-main-breaker.118634/
https://forums.mikeholt.com/threads/multiple-conductors-under-one-lug.36521/
https://forums.mikeholt.com/threads/two-conductors-under-same-lug-on-line-side-of-mb.134417/

Due to last minute design changes, wondering if a 6AWG wire can be tapped with a 4/0 wire on the load side of CB. It's a control panel, 6 AWG wire tap is allowed. It's a one conductor lug terminal.
Quick answer is NO, 110.14(A) violation. But maybe there are any considerations allowing a comparatively small wire to be connected together with a much larger wire. Other solutions is to use multiwire terminals, but it's not desirable in this situation.
 
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The terminal would need to be listed for use with more than one conductor. If it is so listed you would still need to follow the conductor size combinations that the manufacturer has dictated as part of its listing.
 
LarryFine said:
How about these?

ILSCO KUP-L-Tap Insulation Piercing Copper Connector Dual Rated Main Conductor Range 4/0-4 Tap Range 6-14 Tin Plated UL CSA (IPC-4/0-6-B)

ILSCO KUP-L-Tap Insulation Piercing Copper Connector Dual Rated Main Conductor Range 4/0-4 Tap Range 6-14 Tin Plated UL CSA (IPC-4/0-6-B)
www.lightingsupply.com www.lightingsupply.com
Click to expand...
Not sure if it is a good solution for feeding VFD.

infinity
The terminal is listed for one #4-250kcmil conductor. It's an Eaton 200A breaker. Considerations are that the small wire will perfectly mesh with the large wire to form a solid reliable electrical connection. The question is, if there are any articles to justify it.
 
+1 infinity

As an inspector I would tag it--2 conductors is 2 conductors regardless of size
 
AFAIK there are no code articles which would permit this installation. The only way to get the installation passed would be to either do something with the two conductors that makes them 'officially' into 1 conductor (perhaps there are 'pin adapters' rated to take 2 conductors), or to get the breaker evaluated by UL for the particular conductor combination you wish to use. The installation is _possibly_ just fine, simply not tested for listing.
 
Nigeno said:
I cannot open the pictures - "You do not have permission to view this page or perform this action. "
Click to expand...
Don’t know why, try googling Burndy BIBD2502. The picture they may show might be three port, but the part number is a two port. There are several manufactures that make this type of insulated lug, just be sure to get the pass through model, it will take up a lot less room.
 
Nigeno said:
Found similar threads:
https://forums.mikeholt.com/threads/multiple-wires-on-each-lug-of-a-panelboard-main-breaker.118634/
https://forums.mikeholt.com/threads/multiple-conductors-under-one-lug.36521/
https://forums.mikeholt.com/threads/two-conductors-under-same-lug-on-line-side-of-mb.134417/

Due to last minute design changes, wondering if a 6AWG wire can be tapped with a 4/0 wire on the load side of CB. It's a control panel, 6 AWG wire tap is allowed. It's a one conductor lug terminal.
Quick answer is NO, 110.14(A) violation. But maybe there are any considerations allowing a comparatively small wire to be connected together with a much larger wire. Other solutions is to use multiwire terminals, but it's not desirable in this situation.
Click to expand...

Insulation piercing connectors are the solution I'd pick. This doesn't sound like a situation where the factory terminal is built for two wires.

One example is some 15A breakers, like QOB breakers, are listed for two wires per terminal in certain size combinations. These terminals have a shape that allows both wires to seat in separate parts of the terminal.

Another example is "snowman" shaped lugs, that are listed for two wires. You usually see this in the 250A to 400A range of equipment. It is rare that an ordinary round lug is listed to take two wires.
 
I have worked on UL508 control panels, and noted the common method of multiple wires in one terminal block ( din rail type). The mfg instructions do not prohibit more than one wire per terminal. Rather its based on the total cross sectional area of the wires. I dont recall if UL 508 has the restriction of one wire per terminal.
 
The insulation-piercing tap to which I linked is certainly the easiest to install, even hot as long as it's unloaded.
 
tom baker said:
I have worked on UL508 control panels, and noted the common method of multiple wires in one terminal block ( din rail type). The mfg instructions do not prohibit more than one wire per terminal. Rather its based on the total cross sectional area of the wires. I dont recall if UL 508 has the restriction of one wire per terminal.
Click to expand...

Yes, it's a control panel that is governed by UL508 standard. But wouldn't it be regulated by NEC as well?

The solution for this case would be using multiwire terminals available for the Eaton MCCB that have 3 wire listed per lug. I just didn't want to go this path as rewiring would be required.

LarryFine said:
The insulation-piercing tap to which I linked is certainly the easiest to install, even hot as long as it's unloaded.
Click to expand...

For the industry, the control panel is designed for, it's not acceptable. But, thanks for your input.
 
My vote in order would be

1- The multiport Eaton Lugs for the breaker itself
2- Power Distribution Block installed on the load side of the breaker
3- The Tap Lug in post #5
4- The Hot Tap on post #2

JAP>
 
Nigeno said:
Yes, it's a control panel that is governed by UL508 standard. But wouldn't it be regulated by NEC as well?
Click to expand...
The NEC does not cover the internal wiring of a listed control panel. It covers the load and line side wiring. For the many control panels I have installed, the AHJ opens the control panel door, sees the UL listing label and looks no further.
 
tom baker said:
The NEC does not cover the internal wiring of a listed control panel. It covers the load and line side wiring. For the many control panels I have installed, the AHJ opens the control panel door, sees the UL listing label and looks no further.
Click to expand...

Sorry, I didn't get right your question. The panel is not UL listed. Though, to be certified and code compliant it should be designed to UL508A and NEC standards. That's what I meant.
 
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