110.26 (C) (2) Large Equipment

[charlie b]

I am reviewing a design that has a 2500 amp Main Service Board (MSB) that appears (from the plans) to be wider than 6 feet. However, all the breakers are on the left half, and the right half is nothing more than a chase to bring conduits to higher floors. Does the Large Equipment rule come into play here? Can we say that the MSB is, in fact, only 3 feet wide, and the chase to the right is not part of the MSB?

 

[augie47]

That is an excellent question. From reading (C)(2) if I were to make the call I would consider the MSB to be 3' as that is the only portion containing OC devices.

 

[infinity]

IMO by the Article 100 definition of equipment you would need to include this section as part of the 6' width measurement unless it clearly falls under something more specific like a junction box.

Equipment. A general term, including fittings, devices, appliances, luminaires, apparatus, machinery, and the like used as a
part of, or in connection with, an electrical installation.

 

[JGinIndy]

I look at the total foot print of the equipment as the determining factor.

 

[don_resqcapt19]

I had the length removed from this section, but it was only gone for one code cycle. It remains my opinion that the triggering factor should be the electrical rating and not the physical size of the equipment.

In this case, if the chase is part of the equipment, that is supplied as one package, the total length of the equipment is what you use to apply the code section.