SERVICE EQUIPMENT

Greenboy

Member
Location
Seattle, WA
Are there any code violations, or utility requirements(additional requirements that I should look into), to install a 6 disconnect service rated electrical gear, rated at 1600 amps, 480/277 V, and utilities feeding it with 1200 amps, 480/277 V. Assume that the AIC ratings are good.

I assume this will suffice, by providing a placard that states the voltage, and ampacity not exceeding 1,200 amps, along with the AIC calculations.
 

iwire

Moderator
Staff member
Location
Massachusetts
As soon as you have more then one service disconnection means the service conductors need only be sized for the calculated load.

The sign while a nice touch is not required.
 

jumper

Senior Member
While the other info is nice as Iwire stated the only marking/sign that I know of that is required is some type of identification stating that it is a/the service disconnect.

230.70(B) Marking. Each service disconnect shall be permanently
marked to identify it as a service disconnect.
 

kwired

Electron manager
Location
NE Nebraska
Even though you have more then 1000 amps total capacity, the ground fault protection covered by 230.95 is not needed if none of the individual disconnects are 1000 amps or more.

Good or bad that is a way around needing to use the GFP.
 

Greenboy

Member
Location
Seattle, WA
Thank you all for replying.

Should I be concerned that the Electrical utility company will not approve a larger rated gear(1,600 amps), and all they are providing is 1,200 amps?

:?
 

Iron_Ben

Senior Member
Location
Lancaster, PA
Not at all. That's on them, in the extremely unlikely event that your 1600 amps worth of connected draws a sustained 1400 or 1500 amps ands melts the POCO's equipment. The power company is governed by the NESC, not the NEC, and the two don't have much common ground. I guess if I had to pick a ratio of our capacity to customer's main breaker, it would have been often 1:2 and at times 1:4 or even 1:6. Just as an example, for an 800 amp 208Y/120 gang metered six pack at a strip mall or similar, we would have the owner supply two 4" conduits. We'd pull 350 MCM _aluminum_ quad in one and the other would be a spare. Never burned one up, and never pulled anything in the spare pipe. Lots of them in service, for lots of years.
 

Fitzdrew516

Senior Member
Location
Cincinnati, OH
While the other info is nice as Iwire stated the only marking/sign that I know of that is required is some type of identification stating that it is a/the service disconnect.

230.70(B) Marking. Each service disconnect shall be permanently
marked to identify it as a service disconnect.
Yep! I'm actually working on a job right now with almost the exact set up the OP is asking about. All is compliant here... except of course for that clearance (or lack there of). :happyno:
 

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kwired

Electron manager
Location
NE Nebraska
Chances are their transformer is not rated 1600 amps either. They often size equipment to expected load - and consider how long peak demands will last as well. If peak load is less then 6-8 hours but then normally has a cool down period they will let equipment run into a sort of service factor range. But also remember if they burn up their equipment it is outside and not so likely to burn down your building unlike what may happen if you under size things inside the building and it burns up.
 
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