DIY Home Improvement Forum banner

1 - 11 of 11 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1
I've got a 100amp subpanel from a 200amp service planning on using #3 copper THHN.

The nuetral bar on the main service is only large enough to handle #6.

Can I run two #3 hots and two #6 nuetrals instead of two #3 hots and 1 #3 nuetral?
 

·
Sparky
Joined
·
706 Posts
no.

you need to buy an "add-a-lug" for your main panel. if you tell me which brand i can try to pull a cat # for you
 

·
Super Moderator
Joined
·
14,020 Posts
There are lug kits that will fit in the screw holes in the buss. For a Square D panel you would use a LK70AN. You can google the image to see what they look like.
 

·
Registered
Joined
·
3 Posts
Discussion Starter #5
Nice!

Had no idea they made these, I'll have to try and see what my type my panel will take the LK70AN looks like it would work if those two prongs each go into one screw hole.

I'll upload a picture of my main panel if I'm having some issues.

Thanks Everybody.
 

·
JOATMON
Joined
·
15,340 Posts
I've got a 100amp subpanel from a 200amp service planning on using #3 copper THHN.

The nuetral bar on the main service is only large enough to handle #6.

Can I run two #3 hots and two #6 nuetrals instead of two #3 hots and 1 #3 nuetral?
You may already understand why.....but just in case....

While it seems logical that 2 #6's are equal to 1 #3.....they are not...but more importantly....if one of the #6's were to come loose, now all of the return current would be in the other #6 wire......result may not be pretty.
 

·
Registered
Joined
·
90 Posts
You may already understand why.....but just in case....

While it seems logical that 2 #6's are equal to 1 #3.....they are not...but more importantly....if one of the #6's were to come loose, now all of the return current would be in the other #6 wire......result may not be pretty.
I agree with the answer that you should NOT use two #6s in place of a #3. But I did the math and the total area is amazingly close. A #3 AWG has a diameter of 0.2294 inches giving it a cross-section area of 0.041331 sq inches. A #6 has a diameter of 0.1620 inches. Two #6s have a total area of 0.041224 sq inches. It doesn't work out that close for any other wire size. For example, two #12s (with total area of 0.010255 sq inches) do not equal a single #6 (with area of 0.020612 sq inches).
 

·
Banned Electrician
Joined
·
230 Posts
I've got a 100amp subpanel from a 200amp service planning on using #3 copper THHN.

The nuetral bar on the main service is only large enough to handle #6.

Can I run two #3 hots and two #6 nuetrals instead of two #3 hots and 1 #3 nuetral?
That panel should already have a neutral lug that is the same size as the lugs for hots.


310.10(H)
(H) Conductors in Parallel.
(1) General. Aluminum, copper-clad aluminum, or copper
conductors, for each phase, polarity, neutral, or grounded circuit
shall be permitted to be connected in parallel (electrically
joined at both ends) only in sizes 1/0 AWG and larger where
installed in accordance with 310.10(H)(2) through (H)(6).
 

·
JOATMON
Joined
·
15,340 Posts
I agree with the answer that you should NOT use two #6s in place of a #3. But I did the math and the total area is amazingly close. A #3 AWG has a diameter of 0.2294 inches giving it a cross-section area of 0.041331 sq inches. A #6 has a diameter of 0.1620 inches. Two #6s have a total area of 0.041224 sq inches. It doesn't work out that close for any other wire size. For example, two #12s (with total area of 0.010255 sq inches) do not equal a single #6 (with area of 0.020612 sq inches).

But still are not equal......the 2 #6's are 0.3% smaller....

(shssssss....don't want to encourage the OP)

Yea....I know....so close they might as well be equal.....just don't want to give anyone any ideas.....
 

·
Registered
Joined
·
3 Posts
Discussion Starter #10
Picked up the add-a-lug last night and installed the panel.

I hear what you guys are saying about the parallel neutral, someone suggested it to me and it didn't sound kosher to me either.

Thanks again for the advice.
 
1 - 11 of 11 Posts
Top