Engineering

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stillastudent

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I am inspecting a college campus building that is being remodeled and have questions about the engineering. This building has a 200 amp feeder that feeds two, 200 amp panels groupled together on the 2nd floor and then two, 200 amp panels groupled together on the 3rd floor. All panels are feed through panels. The feeder and panels are rated for the calulated load that each panel has. This installation does not seem to allow anything for future growth though. I can not seem to find anything in the NEC that would prohibit this installation but I'm uncomfortable with approving it. The project manager for the school does not seem to realize that they do not have 200 amps capacity at each 200 amp panel. I would be happy to have views and input from other inspectors on this.
 
As an electrical inspector, you should be acutely aware of the language in 90.1(B) of the NEC.
 
I run into this very issue on nearly a daily basis, especially at commercial shell space.

As long as the submittal documents (plans) are compliant with the code and accurately account for the scope of work under the open permit, and all installations are made per approved plans and in compliance with the code, the decision is easy...

It's approved.
 
stillastudent said:
..This building has a 200 amp feeder that feeds two, 200 amp panels groupled together on the 2nd floor and then two, 200 amp panels groupled together on the 3rd floor. All panels are feed through panels. The feeder and panels are rated for the calulated load that each panel has. This installation does not seem to allow anything for future growth though...
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Ask the project manager if he is content with the calculated load at all four panels; tell him he should confirm these loads with his electrical engineer. Tell him he only has ONE 200A circuit, feeding four sub panels.
Prompt him that this circuit may overload or be at capacity soon. I recommend you do this in writing and cc the Architect and the Principle your concern is legit.
 
Sounds like office space? The engineer probably used Table 220-3(A) ? 4 ? VA per sq ft ? for the projected calculated load. This may be just fine for general lighting and general purpose receptacles but not for large printers/heaters/kitchens/refrigerators/wet bars?

The shell distribution probably handles the larger items like HVAC and exhaust motors. Either way your concern is good to question this application.
 
The first question is: what is your role in this?

If you are working for the AHJ, trying to enforce a requirement for future expansion capability, then IMHO you are overstepping your authority, unless your local jurisdiction has amended the NEC to require a certain amount of expansion capability.

If you are working for the school, helping them to catch errors in design, then you _may_ have caught a good issue for value engineering; in this case paying a bit more now for enhanced long term value in the form of cheaper expansion.

It is entirely possible that total building calculated load is much less than 200A, in which case there is already lots of room for expansion.

Given the costs of copper, expansion capability may be a much better value in the form of extra conduit than extra wire.

-Jon
 
stillastudent said:
The feeder and panels are rated for the calulated load that each panel has. This installation does not seem to allow anything for future growth though. I can not seem to find anything in the NEC that would prohibit this installation but I'm uncomfortable with approving it.
Click to expand...
Okay, so what are the specific requiremnents that you believe should be adhered to?
 
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