switchgear clearances

[GerryB]

I am confused reading 110.34. We have a 13.8 gear, i am thinking condition 1. You can open the back to get to the bus. I don't understand the last sentence "Distances shall be measured from the live parts, if such are exposed, or from the enclosure front or opening if such are enclosed". So would you need 5 feet from the wall (block wall) to the cover or could you remove the cover and measure to the live parts?

 

[infinity]

in general you measure from the cover if the live parts are enclosed. Same thing applies at lower voltages.

 

[steve66]

Not sure about 13.8 gear, but for 480V just because the back is removable doesn’t mean you need the full working clearance to the back.

Any “hot” work is normally done from the front. So the back clearance can often range from none required (switchboard right against a wall) to something like 30” (enough to access the busses while deenergized).

Manufacturers cut sheets usually state what is required for any necessary side or rear access.