VE Question

A

Alwayslearningelec

Senior Member
Location
NJ
Occupation
Estimator
So MDP to the (7) sub panel is an average of about 80' each.
Wire is run in RGS conduit.

I'm thinking instead of running (7) separate 3/4" conduits it may be more efficient to combine. Obvious need to derate.
If I was to combine two runs( that would be 2#6's and I'm assuming a neutral and ground) I would be at the 4-7 conductor derating and 80%. Using the 90 degree column I still get 60A? Is that correct for the 60A circuits. Obviously have to upsize conduit.

Last pic is typical sub panel schedule.


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Last edited:
Alwayslearningelec said:
If I was to combine two runs( that would be 2#6's and I'm assuming a neutral and ground) I would be at the 4-7 conductor derating and 80%.
Click to expand...
Sounds good with 80% because you'll have 6 CCC's in each raceway. The 70 amp feeder will require larger conductors.
 
The wire type EGC for the 70A feeder is larger than the 60As so just be careful that if you combine that feeder in the same conduit, and there is a wire type EGC, it is sized to the 70A feeder.

When you combine the feeders you can simplify it to 1 EGC per conduit (if using wire type EGC).
 
infinity said:
Sounds good with 80% because you'll have 6 CCC's in each raceway. The 70 amp feeder will require larger conductors.
Click to expand...
Correct about the 70A? 6CCC's because your including neutral? When you calculating conduit fill do you include ground? 1-1/4" may work.
 
Alwayslearningelec said:
Correct about the 70A? 6CCC's because your including neutral?
Click to expand...
Yes the neutral is considered a CCC in these feeders. If the neutrals weren't a CCC you could have put 3 sets of #6 in each raceway with the same 80% derate.
Alwayslearningelec said:
When you calculating conduit fill do you include ground? 1-1/4" may work.
Click to expand...
Yes the word fill applies to any conductor that is filling the raceway.
 
The VA per line.
2 is shown on A while listed on B
Looks like they went B,C,A on the even side.
I did not run the numbers. Just looked odd.
Hopefully did not change the VA per line for the max line load for sizing.
 
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