Line parallel conductor and load single conductor

Charlypt

Member
Location
Florida
Occupation
Electrician
If a feed with parallel conductors is used, is it possible to use a connection for the load using a single conductor, or vice versa?
Applied to meters cans, disconnect switches, or any switchgear.
In my opinion it is possible, as long as both are rated for the same amperage, but I would like to know if the NEC says anything about it.

We could extend the question even if we used different material at the input and output, such as copper vs aluminum; or if we used a different size of wire.
In summary, can the input be different from the output in configuration, size and material as long as they satisfy the desired amperage?
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
If a feed with parallel conductors is used, is it possible to use a connection for the load using a single conductor, or vice versa?
If you're asking if it's okay to tap one wire of a parallel set, no.

Each tap must connect to all paralleled conductors.

In summary, can the input be different from the output in configuration, size and material as long as they satisfy the desired amperage?
If you're asking if it's okay to transition from paralleled conductors to a single adequate conductor, yes.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Yes, for example you can go from 2 sets of #3/0 to a single set of 600 kcmil for a 400 amp feeder. The reverse is also code compliant.
 

jap

Senior Member
Occupation
Electrician
If a feed with parallel conductors is used, is it possible to use a connection for the load using a single conductor, or vice versa?
Applied to meters cans, disconnect switches, or any switchgear.
In my opinion it is possible, as long as both are rated for the same amperage, but I would like to know if the NEC says anything about it.

We could extend the question even if we used different material at the input and output, such as copper vs aluminum; or if we used a different size of wire.
In summary, can the input be different from the output in configuration, size and material as long as they satisfy the desired amperage?

Think of any electrical device whether it be a disconnect, meter, panelboard, etc,,,,,
If it weren't allowed they wouldn't be able to use lugs, that transistion to buss bars that transition through contacts of a breaker that eventually transistion wire type aluminum or copper conductors etc....

JAP>
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
In summary, can the input be different from the output in configuration, size and material as long as they satisfy the desired amperage?
Using a disconnect switch as an example the answer is yes you can change from multiple sets to a single set. And yes you can change from one conductor material another.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
Read 310.10(G) again particularly subsection(2).

Basically you can change parallel conductors to single conductors (assuming ampacity requirements are met) at any point in a circuit, so long as the parallel conductors end at the same place. I think most will interpret that as being inside the same enclosure, or the same section of any kind of multi-section equipment. Does not matter if the change happens by a splice, or at a switch or breaker, or by some legit multi-conductor termination lug, or what have you.
 

Fred B

Senior Member
Location
Upstate, NY
Occupation
Electrician
Don't forget the limitation placed on the use of parallel conductors found in 310.10(G) that generally they must 1/0 or larger, with a few exceptions.
 
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