Parallel Conductors

Status
Not open for further replies.
B

Bob Clukey

Member
Could someone give me a practical explanation of what this section is trying to convey?

(3) Separate Cables or Raceways. Where run in separate
cables or raceways, the cables or raceways with conductors
shall have the same number of conductors and shall have
the same electrical characteristics. Conductors of one
phase, polarity, neutral, grounded circuit conductor, or
equipment grounding conductor shall not be required to
have the same physical characteristics as those of another
phase, polarity, neutral, grounded circuit conductor, or
equipment grounding conductor.

Thanks!
 
Also do not run the paralleled wires in cables or raceways such that the raceway environment is different from one wire to another in the parallel set.

For example do not parallel an individual 2/0 wire with another 2/0 wire which is part of a three wire cable.
 
One other note. If you elect to parallel conductors and for Phase "A", for example, you use one 75ft long 2/0 AL XHHW conductor, the other parallel Phase "A: conductors must be 75ft long 2/0 Al XHHW, however, the requirement for XHHW conductotrs or AL conductors would not carry over to say the grounded or grounding conductor.
 
Basically each conductor used in a parallel group must be identical in every way. This requirement is in place to ensure the current divides as evenly between conductors as possible.


As Augie mentioned that requirement is only per each paralleled group.



You could wire it up phase A, B, C, N and grounding all THHN copper.

But you can also mix it up if you wanted to.

  • Phase A two sets of THWN copper
  • Phase B two sets of XHHW coppper
  • Phase C two sets of RHW Aluminum
  • Neutral two sets THHN copper
  • Grounding two sets THHN Aluminum.


Now if they were all going in a common raceway you could even mix it up further as long as each set was of sufficient ampacity.

  • Phase A two sets of THWN copper
  • Phase B one XHHW coppper
  • Phase C three sets of RHW Aluminum
  • Neutral two sets THHN copper
  • Grounding one THHN Aluminum.
 
iwire said:
Basically each conductor used in a parallel group must be identical in every way. This requirement is in place to ensure the current divides as evenly between conductors as possible.


As Augie mentioned that requirement is only per each paralleled group.



You could wire it up phase A, B, C, N and grounding all THHN copper.

But you can also mix it up if you wanted to.

  • Phase A two sets of THWN copper
  • Phase B two sets of XHHW coppper
  • Phase C two sets of RHW Aluminum
  • Neutral two sets THHN copper
  • Grounding two sets THHN Aluminum.


Now if they were all going in a common raceway you could even mix it up further as long as each set was of sufficient ampacity.

  • Phase A two sets of THWN copper
  • Phase B one XHHW coppper
  • Phase C three sets of RHW Aluminum
  • Neutral two sets THHN copper
  • Grounding one THHN Aluminum.
Click to expand...
Got some left over wire in the storage shed you want to get rid of?
 
Status
Not open for further replies.
Top