I have an old MCC which does not meet Art 110.09 and 110.10. It will be replaced with a higher rated switchboard since no motor loads are fed of the MCC.
In the past, some mechanical company built a huge plenum 3'-4" close to the MCC. the new Switchboard will have the same depth and subsequently, we will end up with the deadfront being only 3'-4" away from a conductive plenum.
As you all know, this does not satisfy 110.26. At 480V and Condition 2, I need at least 3'-6".
There is (3) options.
1. Relocate the equipment. This is impossible because there is no other real-estate available.
2. Roll out administrative procedures which prohibit any energized work. I am banking on 110.26(A) "...likely to require examination, adjustment, servicing, or maintenance while energized..." When it's free of voltage, there is no risk.
3. Find a suitable insulation coating and spray it over the plenum to electrically insulate it. Does anybody have any coating recommendation? I found spray cans and but I am looking for a commercial 8x10 ft application.
In the past, some mechanical company built a huge plenum 3'-4" close to the MCC. the new Switchboard will have the same depth and subsequently, we will end up with the deadfront being only 3'-4" away from a conductive plenum.
As you all know, this does not satisfy 110.26. At 480V and Condition 2, I need at least 3'-6".
There is (3) options.
1. Relocate the equipment. This is impossible because there is no other real-estate available.
2. Roll out administrative procedures which prohibit any energized work. I am banking on 110.26(A) "...likely to require examination, adjustment, servicing, or maintenance while energized..." When it's free of voltage, there is no risk.
3. Find a suitable insulation coating and spray it over the plenum to electrically insulate it. Does anybody have any coating recommendation? I found spray cans and but I am looking for a commercial 8x10 ft application.