Question about Sizing a Sub-panel in my Detached Garage

[The Great Sarducci]

Good Afternoon,

I'm planning on installing a new 100 amp sub-panel in my detached garage (I live in a typical single-family dwelling). I've got everything laid out and planned according to code, however there is one aspect of the installation that I'm now unsure of after mulling it over in my head a bit. My concern now is whether or not it would be acceptable to install a sub-panel rated at 100A fed by my main service panel also rated at 100A? The fact that I chose a 100 amp panel for my garage is solely because of cost and availability of a 70 amp panel which also supports 6-8 full-sized breakers. The 100A is simply more cost effective and easier to deal with in this case. I never planned on actually feeding the panel with 100A from the main panel in the house. I'll probably feed it with a 70 amp breaker, but will run #2 Aluminum out to the garage just in case I ever need to utilize it as a 100A sub panel.

But now back to my question; Does anyone here know if there is an article in the NEC which prohibits installing a 100A sub-panel if the main service panel feeding it is also 100A? Or more specifically, does the main service panel have to be rated higher than a sub its feeding? If so, would it also still be a code violation in the case where; although the sub-panel is marked/rated as a 100A load center, the panel disconnecting means (in this case the CB at the main panel), is protecting the panel at say 70 amps?

Any help on this situation would be most appreciated.

Thanks,
Ryan

 

[charlie b]

I am closing this thread in accordance with forum rules. This forum is intended to assist electricians, electrical contractors, inspectors, engineers, and other members of the electrical profession with their job related duties. If you are not an electrician, we are not permitted to help you perform your own electrical troubleshooting, installation, or maintenance work.

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