NEC Working Space Clearances

[fosmeister]

I'm designing the install of a switchboard in a tight spot. The dedicated electrical space above the switchboard, per NEC 110.26F, is OK. The working space complies to NEC 110.26A, however, directly above the working space is an air handling unit. This is a chilled water unit with supply/return lines however these do not intrude on the dedicated electrical space, above the switchboard. NEC 110.26F talks about how sprinklers are allowed within the dedicated electrical space, with some conditions. The workbook examples show a sprinkler above the working space as being allowed even though this section talks about the dedicated electrical space, not working space. The example doesn't show a sprinkler above or inside the dedicated electrical space.

Question: Is the working space the same as the dedicated electrical space and has the same restrictions per 110.27, i.e. only sprinklers above the working space?

Does this situation described conform to the NEC?

Thanks,

Fosmeister

 

[infinity]

Question: Is the working space the same as the dedicated electrical space and has the same restrictions per 110.27, i.e. only sprinklers above the working space?

The working space is different in that piping systems are permitted above it without the need for protection from leaks, condensation etc. If you ran a water pipe 7' above the dedicated space it would require a drip pan or some other form of protection for the equipment below it. This protection would not be required if the same pipe were run above the working space.