commericial upgrade

[leviticus]

i havent had much commericial exprience. i am sure you gentalmen can help. i have been asked to do an upgrade on a commericail building its is an overhead service approx. usinin 400 amps, i currenly have this to work with: the imc comes down into a 30x18x10 j box through the bottom of this j box an offset to meter face, out of the left side i have a 3.5x4 nipple to a 10x40x10 gutter out of this gutter through parrell 250 mcm thhn runs they have split bolted two 200 amp subs and also two 60 amp disconnects and a 60 amp sub panel, to feed these 60 amp dissc. and sub they used 1o thhn out of the split bolt. My problem is i cant reuse the 30x18x10 j box because it hase no cover either does the meter pack , can i use a k4ut 400 amp meter pack and run parallel 250 mcm up through the weather head w/ out havin to repace from the gutter box on?

 

[hurk27]

Re: commericial upgrade

You said "meter pack" does this mean there are more than one service or is this just what your calling the meter? If it is one service check with the serving utility and see if you can use a 320 meter fitting with double barrel lugs in it. Then just run 3 ought cu. or 4 ought al. to each panel then just sub feed the 60 amp panel out of one of the 200 amp panels. If the panels are close enough to the outside wall and local codes permit these can be main breaker panels that eliminate the need for outside disconnects.

For the riser to the service drop.
Why 250 MCM? even al. only requires 4 ought paralleled, and if cu. you can use 3 ought. But again check with your utility as they might not want paralleled conductor to hook up to.

 

[bfd]

Re: commericial upgrade

Looks to me like you need to talk the POCO, and an inspector, to get more insight on how to perform this upgrade in your area. Many POCO are letting you install self contained 400 & 600 amp meter bases.