ECN Forum Forums Code Related Discussion NEC & other Code issues Quadplex Size for 200A

What size quadplex should be used for an overhead line for 200 A. ? Table 310-17 says 1/0 for 90ºC wire if it qualifies, and that seems to be the size that the PoCo uses.

This is for a dairy barn on the load side of the disco.

Also, the pole that will have the tap is only triplex, Bond the Neutral and Ground at the pole where the tap is made, or? It may be upgraded in the future.

Thanks

-Virgil

It seems that you are on the money if the terminals are rated for 90C. How long of a span is it? Around Phila., aerial PECO spans are usually only #4 al. even on 200A services. I used #6 quadplex for an overhead span of about 75' once, and as I was pulling it into the wedge clamp, it got pretty heavy. Have you ever used such large quadplex before? Is the pole the service point? Couldn't you bond in the disconnect?

hmmm,
a quick check of the good book,,,

as far as the MBJ, check out 250-30 , especially EX # 1.

sizing- 215-2 ( ampacity)

225-6 ( size)

547-8(c) i beleive throws out 250-32(b)(2) if i'm reading it right.


also why 310-17? does 310-20 look any better?




[This message has been edited by sparky (edited 06-07-2001).]

I think Table 310.16 would have to be used for quadruplex cable. I'm really not 100 percent certain. Table 310.17 is for single conductors. Table 310.16 would require 4/0 conductors if the terminals at the disconnect and the main breaker in the panelboard in the dairy barn are rated for 90 deg. In the area where I live it is not unusual for the Power Company to install triplex or quadruplex service drop conductors of a smaller size than the Contractors service conductors. They are not required to comply with the NEC for such an installation. However, for feeder conductors whether indoors or outdoors Table 310.16 should be used. Just my opinion....


Frank (cinkerf)

I will address this part of your post: Also, the pole that will have the tap is only triplex, Bond the Neutral and Ground at the pole where the tap is made, or? It may be upgraded in the future.

I would ground and bond at the pole. You are running a quadruplex cable to the dairy barn panelboard. Isolate the neutral in the panel, drive a ground rod and connect to the "fourth" wire. Also bond any copper water lines that may exist.
What do you think?

Frank (cinkerf)

That was the plan, wanted to know if it was the right plan though!

Thanks!

-Virgil

Hey Virgil,
Do you have more pics for Photos/Discussion?
I really enjoy yours. You're the only one around that can catch 250+ violations in 1 photo!...scott

I feel that it is in compliance with the NEC