# termination of paralleled conductors

#### sshane

##### New member
A 400 amp main feeds 2 panels, the feed comes underground and into 1 panel that feeds to the other panel adjacent to each other. Parallel feeds split in two 2" pipes, could I feed 1/2 of the paralleled feed into 1 panel and half in the other and jumper between panels with paralleled feeders

#### augie47

##### Moderator
Staff member
Tell us a bit about the panels. MB/ML ? size ?

#### Dennis Alwon

##### Moderator
Staff member
I don't see how you could could the lengths equal. Can you install a trough under the panels tap from there? It is an interesting question and have never seen it done that way. I just don't see how it could work.

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#### infinity

##### Moderator
Staff member
uc
A 400 amp main feeds 2 panels, the feed comes underground and into 1 panel that feeds to the other panel adjacent to each other. Parallel feeds split in two 2" pipes, could I feed 1/2 of the paralleled feed into 1 panel and half in the other and jumper between panels with paralleled feeders
This would make the conductors tap conductors and would therefore need to follow the tap rules in Article 240.

Welcome to the Forum.

#### charlie b

##### Moderator
Staff member
. . . could I feed 1/2 of the paralleled feed into 1 panel and half in the other and jumper between panels with paralleled feeders
If you do that, the conductors will no longer be in parallel. But why should they be anyway? Why do they need to be in parallel? If you supply two panels from the same source, each will normally get its own feeder.

#### infinity

##### Moderator
Staff member
If you do that, the conductors will no longer be in parallel. But why should they be anyway? Why do they need to be in parallel? If you supply two panels from the same source, each will normally get its own feeder.
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I think that the issue is he has a 400 amp OCPD to feed 2-200 amp panels. That kind of limits his options.

#### petersonra

##### Senior Member
A 400 amp main feeds 2 panels, the feed comes underground and into 1 panel that feeds to the other panel adjacent to each other. Parallel feeds split in two 2" pipes, could I feed 1/2 of the paralleled feed into 1 panel and half in the other and jumper between panels with paralleled feeders
If he jumpers them at the end as he said in his OP they are now paralleled.

310.4 Conductors in Parallel. Aluminum, copper-clad
aluminum, or copper conductors of size 1/0 AWG and
larger, comprising each phase, polarity, neutral, or
grounded circuit conductor, shall be permitted to be connected
in parallel (electrically joined at both ends).
I would say he has electrically joined them at both ends.

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#### jim dungar

##### Moderator
Staff member
If he jumpers them at the end as he said in his OP they are now paralleled.

I would say he has electrically joined them at both ends.
Sounds like discussion we had concerning 'ring' circuits.

#### ggunn

##### PE (Electrical), NABCEP certified
If he jumpers them at the end as he said in his OP they are now paralleled.

I would say he has electrically joined them at both ends.
Incoming!

#### charlie b

##### Moderator
Staff member
If he jumpers them at the end as he said in his OP they are now paralleled.
Sounds like discussion we had concerning 'ring' circuits.
Incoming!
I wondered if anyone would bring that up. As I recall, we never did come to a consensus on that one. :happysad:

#### iwire

##### Moderator
Staff member
Sounds like discussion we had concerning 'ring' circuits.
Yes, and I will run from this one as well.

But I think the real issue is the 200 amp panels as Rob mentioned,

#### petersonra

##### Senior Member
As far as I can tell, the code does not prohibit "ring" circuits as long as they meet all the requirements of paralleled conductors. The critical one being they have to be 1/0 or larger.

#### jim dungar

##### Moderator
Staff member
But I think the real issue is the 200 amp panels as Rob mentioned,
Did I miss where the OP said they actually were 200A panels?

This is not the first time I have been asked this question. Both conductors into Panel 1 and then looped over to Panel 2 requires a second set of lugs. One set into Panel 1, the other set into panel 2, and a jumper between them can physically be done with one set of lugs.

#### infinity

##### Moderator
Staff member
Did I miss where the OP said they actually were 200A panels?

This is not the first time I have been asked this question. Both conductors into Panel 1 and then looped over to Panel 2 requires a second set of lugs. One set into Panel 1, the other set into panel 2, and a jumper between them can physically be done with one set of lugs.
You're right, he didn't say 2-200 amp panels I made that assumption. hmy: Maybe he will check back in and clarify.

#### petersonra

##### Senior Member
You're right, he didn't say 2-200 amp panels I made that assumption. hmy: Maybe he will check back in and clarify.
why would it matter. as long as the feeder wires are protected properly does it really matter what size the PBs are?

#### charlie b

##### Moderator
Staff member
But we don't know anything about the feeder sizes either. Hello, SSHANE, please fill in some of the missing details.

#### iwire

##### Moderator
Staff member
why would it matter. as long as the feeder wires are protected properly does it really matter what size the PBs are?
If the panelboards are MLO 200s and protected by a 400 amp over current device that would be a violation. But as Charlie said we don't really know anything.

#### infinity

##### Moderator
Staff member
why would it matter. as long as the feeder wires are protected properly does it really matter what size the PBs are?
If the panelboards are MLO 200s and protected by a 400 amp over current device that would be a violation. But as Charlie said we don't really know anything.
Like Bob said a 200 amp MLO on a 400 amp feeder would be a problem.

#### petersonra

##### Senior Member
Like Bob said a 200 amp MLO on a 400 amp feeder would be a problem.
Good point. I would not likely ever spec out a MLO panel, so that had not occurred to me. In any case, the OP only asked about the way he paralleled the conductors. There are all kind of other things he might have done wrong, like not derating since he has at least (6) CCC in the 4" conduit.