Working Clearances (NEC table 110.34(A)) 1

[gregnola]

I have a lineup of 15kV switchgear which will be installed in a prefabricated building. The switchgear has rear access in order to access the bus and incoming & feeder cable terminations. The building manufacturer indicates that NEC 110.34(A) Exception takes precedance here because the end user should not open the rear doors while the gear is energized. Thus, the switchgear can be less than 6'-0" from the wall of the building.

Is this true? Has anyone else run into a similar situation?

Thank you

 

[resqcapt19]

It is very unlikely that you would work on the energized bus, so the exception would apply.
Don

 

[mpparent]

We've used this exception as well.

Mike

 

[BJC]

I have used and tried to use as well. Some AHJ will take the position that even though it's not supposed to be worked on it can be opened when hot.
Opening it up to do an Ir scan is "wokring on it".
It would be wise to get the AHJ to review and respond in writing.

 

[EEJaime]

We also have had local AHJ's require any panel which provides access for any maintenance work, torqueing lugs, performing scans, taking load readings, etc..., be provided with the necessary clearances per the tables. Since it is not normal for these to be opened while energized, the AHJ may allow you to eliminate the clearances, perhaps requiring added signage or something along those lines, but it really is his call. Again, careful with regards to differing opinions between office and field staff of the AHJ's organization. Sometimes what the plan checker says is acceptable, may not be ok with the Electrical Inspectors.