230.70 strikes again

[sceepe]

Got a large commercial service (1600 amps) about 80% complete. AHJ has just decided that length of service entrance conductors is too long and wants an enormous exterior disconnect. Funny thing is, he had no problem with it during plan review. Reading 230.70 commentary, it doesn't look like I have many options. One that I was considering is getting the poco to install disconnect on the pad mount. Much smaller disconnect on the high voltage side. Even if we had to buy the disconnect, it may be cheaper than the secondary side disconnect. Has anybody ever seen a POCO do this?

[ June 01, 2005, 05:16 AM: Message edited by: sceepe ]

 

[iwire]

Re: 230.70 strikes again

Originally posted by sceepe:
AHJ has just decided that length of service entrance conductors is too long and wants an enormous exterior disconnect.

Do you mean the length of the service conductors is to long inside the building from the point of entrance to the disconnect switch?

You said it was fed from a pad mount which suggests the service conductors are underground.

230.6 Conductors Considered Outside the Building.
Conductors shall be considered outside of a building or other structure under any of the following conditions:

(1)Where installed under not less than 50 mm (2 in.) of concrete beneath a building or other structure

(2)Where installed within a building or other structure in a raceway that is encased in concrete or brick not less than 50 mm (2 in.) thick

(3)Where installed in any vault that meets the construction requirements of Article 450, Part III

(4)Where installed in conduit and under not less than 450 mm (18 in.) of earth beneath a building or other structure

Keep the conduits underground or encased in concrete and they are 'outside' the building no matter how far in the building they run.

 

[sceepe]

Re: 230.70 strikes again

Yeah, this is a multi story upfit. The new switchgear is on the second floor. All floors were built but upper floors are unfinished shells with no service supplied at timne of construction. I had to get power to upper floors but service to first floor was sized for first floor only. Easiest solution was to add a second main.

 

[steve66]

Re: 230.70 strikes again

Sounds like it might be easier (or at least cheaper) to encase the service conductors in brick.

Steve

 

[infinity]

Re: 230.70 strikes again

We have done similar installs where we would encase the conduit in concrete. If the conduit is supported by a rack it is important to ensure that the rack can support the weight of the conduit, wire, and concrete. Concrete weighs about 4000 pounds /cu. yd. Additional supports may be necessary. It's not as bad as it sounds and should be a lot cheaper than the huge outside disconnect.

 

[pierre]

Re: 230.70 strikes again

Sceepe
You mentioned that you added a second main. Did you run new service laterals to this main, or did you use the existing service and tap a second main. Your info is a little vague.
As Bob has mentioned, raceways with 2 inches of concrete encasement are considered outside the building and that may be a much more cost effective method.