Electrical service value engineering

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IL94EE

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My firm does almost all the A/E work for a decently-sized school district. However, they recently had someone donate money for a wrestling building, and the donor selected another firm. We're keeping an eye on things yet for the district. The building is being planned to be able to have a swimming pool added in a couple/few years. It was being designed to have a 2000A service, and have extra space in the gear to serve the addition. The building is over budget, and the EE doing the design is proposing cutting back on the cabling coming into the building and the gear ampacity down to 1200A, but have spare conduits to "boost" it back to 2000A someday. His proposal is to not change out the gear to 2000A bussing, but to slap a OCPD on the wall next to it, fed via the currently proposed spare conduits. I haven't been able to come up with a solid code reason for this to not be OK (detective's block, vs. writer's block), but something just doesn't smell right about it. I'm awaiting his riser diagram to see if he's putting in a main in his skinnied up gear, or going rule of 6. Either way, I'm feeling like having a separate OCPD from the main gear just doesn't fly. Can anyone help break my "detective's block" for me?
 
It just appears like they are going to install a 1200A fused main ahead of the 2000A gear in order to reduce/decrease the required conductors. Assuming all required code considerations are made, I don't see how this would be a violation or even a bad practice. At least they are allowing for the future exapansion.
 
No, he's not trying to have a 1200A OCPD ahead of the gear. He's going to have 1200A worth of wire going to a piece of 1200A gear, then also having several spare conduits "off to the side" which can have wire installed in them in a couple years, going to a "parallel piece of gear", for lack of a better explanation. It will all go through the same 2000A CT cabinet for metering, from the same transformer, but then it sort of separates into two separate services in one room. So for simplicity of viewing, think of it as a 1200A OCPD and an 800A OCPD hanging next to each other in totally separate enclosures, fed from the same transformer. Still sound OK?
 
Sounds OK to me. I might be concerned about the proper placement of the N-G bonding connection. It needs to be at the first disconnecting means, and that might not be in the 1200 amp gear.
 
IL94EE said:
. . . think of it as a 1200A OCPD and an 800A OCPD hanging next to each other in totally separate enclosures, fed from the same transformer. Still sound OK?
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But perhaps I am not quite understanding this correctly. Are you saying that the gear will continue to be a 2000 amp rated item, that it will be fed via a 1200 amp OCPD now, and that the same gear (not a separate gear) will be fed via a second OCPD later? In other words, will this thing someday have one set of conductors from the transformer, via a 1200 amp OCPD to the gear, and a second set of conductors from the transformer, via a 800 amp OCPD, to THE SAME GEAR? If that is what you are describing, it is a violation of 240.8.
 
I take it that the present proposal is for a stand alone single 1200A OCPD feeding a 1200A board/panel. Sometime in the future a second OCPD will be added near/next to the original service (using the spare conduits), thereby creating a "6-circuit rule" service.

There is nothing wrong code-wise with this design. In fact, from an arc-flash stand point having an stand-alone/isolated main OCPD is often advantageous.
 
???

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Why not just put in a 2000A frame breaker with a 1200A plug and 1200A trip that way all you have to do later is provide the cable and a new plug. beats buying throw away equipment (posibally) and avoids the N/G problem (potential problem)
 
Jim Dungar is following the proposed service method correctly, at least the way the design engineer has explained his proposal to me thus far. I still await his actual drawings for verification and reviewing.

They aren't going to want to put in the 2000A breaker and gear, since that's where they're trying to save most of the money. Put in 1200A stuff all the way with some spare conduits. And they want to use aluminum bussing in the gear - not my preference, but nothing wrong with it.

Thanks for the feedback. I guess the main place I've thought there would be a code issue was in relation to the rule of 6. I've always had in my mind that the 6 switches need to be in one piece of gear/enclosure since all the cables then land on a common bus, vs. having multiple separate ones adjacent and potentially each set of cables with different lengths going to separate switches. But if there isn't actually a problem with that, then it can fly.
 
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