Parallel Conductors - reduce quantity

[leboot]

Hi Everyone,

I'd like to get some input on 310.10(H) - Conductors in parallel

I had an electrician tell me that you cannot change the quantity of conductors in parallel or their size. (If they start as 6 sets, they have to end as 6 sets and the conductor size can't change). I don't see why it would be an issue if they were:

(1) the same length
(2) same conductor material
(3) same size circular mil
(4) same insulation
(5) terminated in the same manner

For example, could I start at my swbd with 2 sets of 500, transition to 3 sets of 350 for the run, and transition back to 2 sets of 500 at my panel? The circular mil does change, but all of the parallel sets would be the same.

I'm looking at using the parallel rated multiconductor connector. (Voltage drop, oversized conductors, circuit breaker lug issues).

Thanks in advance!

p.s. What do the 5 yellow/gold stars mean on a post?

 

[texie]

Hi Everyone,

I'd like to get some input on 310.10(H) - Conductors in parallel

I had an electrician tell me that you cannot change the quantity of conductors in parallel or their size. (If they start as 6 sets, they have to end as 6 sets and the conductor size can't change). I don't see why it would be an issue if they were:

(1) the same length
(2) same conductor material
(3) same size circular mil
(4) same insulation
(5) terminated in the same manner

For example, could I start at my swbd with 2 sets of 500, transition to 3 sets of 350 for the run, and transition back to 2 sets of 500 at my panel? The circular mil does change, but all of the parallel sets would be the same.

I'm looking at using the parallel rated multiconductor connector. (Voltage drop, oversized conductors, circuit breaker lug issues).

Thanks in advance!

p.s. What do the 5 yellow/gold stars mean on a post?

I see no code issue with this. Keep in mind that at every transition point all conductors would have to be tied together with a common bus or connector.

 

[petersonra]

Hi Everyone,

I'd like to get some input on 310.10(H) - Conductors in parallel

I had an electrician tell me that you cannot change the quantity of conductors in parallel or their size. (If they start as 6 sets, they have to end as 6 sets and the conductor size can't change). I don't see why it would be an issue if they were:

(1) the same length
(2) same conductor material
(3) same size circular mil
(4) same insulation
(5) terminated in the same manner

For example, could I start at my swbd with 2 sets of 500, transition to 3 sets of 350 for the run, and transition back to 2 sets of 500 at my panel? The circular mil does change, but all of the parallel sets would be the same.

I'm looking at using the parallel rated multiconductor connector. (Voltage drop, oversized conductors, circuit breaker lug issues).

Thanks in advance!

p.s. What do the 5 yellow/gold stars mean on a post?

He is correct. So are you.

You can do what you want to do but essentially what you are doing is starting a new set of parallel conductors that follow the same set of rules. And as another poster mentioned, all of the conductors on each phase have to be connected together.

 

[roger]

I'd like to get some input on 310.10(H) - Conductors in parallel

I had an electrician tell me that you cannot change the quantity of conductors in parallel or their size. (If they start as 6 sets, they have to end as 6 sets and the conductor size can't change).

If this is the same electrician that said Polaris connectors need periodic maintenance I'd think about letting things he says go in one ear and out the other.

In reality it sounds as though he is telling you myths he may actually believe

Roger

 

[leboot]

You got it. He knows enough code to sound credible. And he talks louder than I do. I just want to have my ducks in a row before I respond.

That's why I really appreciate this forum...thank you!

 

[Carultch]

For example, could I start at my swbd with 2 sets of 500, transition to 3 sets of 350 for the run, and transition back to 2 sets of 500 at my panel? The circular mil does change, but all of the parallel sets would be the same.

I'm looking at using the parallel rated multiconductor connector. (Voltage drop, oversized conductors, circuit breaker lug issues).

In some cases, that is what you'd have to do to install the total KCMIL needed for voltage drop curtailment. Sure, 600A equipment with 3 parallel lugs on each phase could exist, but good luck finding one. Equipment is usually designed with the most likely number of parallel sets in mind, and the possibility of extreme upsizing is not considered. You'd be stuck if you weren't allowed to use insulated multitap connectors to revise the number of parallel sets. In any case, you have to start and stop each paralleling at the same busbar/connector, to avoid breaking the symmetry.

 

[leboot]

In any case, you have to start and stop each paralleling at the same busbar/connector, to avoid breaking the symmetry.

Carultch - can you describe this busbar connector a little more? Is this something one could add to a switchboard or does it go in another enclosure? Does it require a cover? I'm not familiar with this type of product, but I've heard it mentioned a couple times.

I'm looking at the Polaris parallel rated pre-insulated connectors.

Thanks!

 

[LarryFine]

p.s. What do the 5 yellow/gold stars mean on a post?

Never noticed them but now curious.

Anyone? Frye? Frye? Frye? :?

 

[roger]

Carultch - can you describe this busbar connector a little more? Is this something one could add to a switchboard or does it go in another enclosure? Does it require a cover? I'm not familiar with this type of product, but I've heard it mentioned a couple times.

I'm looking at the Polaris parallel rated pre-insulated connectors.

Thanks!

And that is a very good choice or if you have room look into the Ilsco line of Power Distribution Blocks

Roger

 

[jumper]

Stars denote the "rating" a thread gets by the members who use that function. It is meaningless.

 

[Carultch]

Carultch - can you describe this busbar connector a little more? Is this something one could add to a switchboard or does it go in another enclosure? Does it require a cover? I'm not familiar with this type of product, but I've heard it mentioned a couple times.

I'm looking at the Polaris parallel rated pre-insulated connectors.

Thanks!

I was talking about busbars in general, not necessarily any specific product or way you'd do it. It could be built in the same switchboard, on separate insulating fixtures. It could be a Polaris (or equivalent) multitap connector, which is a busbar that has an insulated container around it. It could be in a separate enclosure, or installed in spare space within the same switchboard. It could occur in a handhole using submersible Polaris connectors. All a design decision. Polaris is a brand name, but it is the most common brand name that is recognized for this family of products. Illsco, Burndy, and Penn Union also make insulated in-line splice reducers and multitaps.

There is a device called a transclosure that one might use in this application, when there are serious quantities of wire to parallel and/or tap. As you might guess, transclosure is a portmanteau of transition and enclosure. Similar to the secondary cabinet of a typical pad-mount transformer, it is an enclosure that contains several busbars with holes for lugs, all mounted on insulating fixtures. We're talking possibly 10+ parallel sets to land on the same phase, where you might anticipate such a strategy.