Conductors in Parallel

Status
Not open for further replies.
R

Ron Hill

Member
Location
Cleveland Ohio
I have a 4000 amp 480V 3phase w/ neutral service to feed from a transformer. I am running 750 AL in 10 conduits. I know the code says that all conductors for each phase must be same length but is there any wiggle room for a few inches in length?
 
It is not physically possible to make any two wires exactly the same length. So wiggle room is necessary and appropriate. Just don't make the differences a large percentage of the overall length.

By the way, a 750 MCM AL conductor is only good for 385 amps. Ten of them will only handle 3850 amps. Is the calculated load for this installation lower than that value? Also, do you have a means for turning the trip point on the main breaker down to 3850 amps? If the answer is No to either question, then you will need a different solution (e.g., 11 sets of 700's or 12 ssets of 600's).
 
Parallel Conductors

Parallel Conductors

We are having some major issues with space in a new Arc Resistant switch gear.
My question seems to be the same as all the others, How much really is a comfortable tolerance?
And am I interpreting it correctly, ALL conductors of ALL phases ALL the same length?
 
SLR said:
We are having some major issues with space in a new Arc Resistant switch gear.
My question seems to be the same as all the others, How much really is a comfortable tolerance?
And am I interpreting it correctly, ALL conductors of ALL phases ALL the same length?
Click to expand...

The parallel phase must be the same length. For instance phase "A" conductors must be the same length but they do not have to be the same length as phase "B" or "C". etc
 
Status
Not open for further replies.
Top