Medium Voltage Clearances

[circuitrider]

I have an existing room in which I need to add a 480V MCC. the maximum spacing that I can achieve between the MCC and an existing 4180V (2400V to ground) switchgear lineup is 4 feet. For condition 3 I would need 5 feet. In the 2014 NEC 110.26(A)(1)(c) allows condition 2 for two 480V lineups facing each other if procedures are in place to keep them from being open at the same time. Is there a provision for allowing Condition 2 to apply for over 600V?

 

[circuitrider]

This may be a moot point since there are procedures in place to prevent any live work.

 

[JRW 70]

This is a far fetched idea, but could you get
a weather proof (Like NEMA 3R or better)
and put this outside? or would that be a
security risk? If the room is too small I
would go out of the room if that was
possible.

I realize this is rather abstract but it may give
a solution to your clearance issues. If the area
is secure enough for the rain-tight MCC you
need

Or

Could you get a variance from your inspecting
authority? From what you said the spacing is
reasonably close to the required clearances,
and your MCC could be in this room.

JR

 

[don_resqcapt19]

.. In the 2014 NEC 110.26(A)(1)(c) allows condition 2 for two 480V lineups facing each other if procedures are in place to keep them from being open at the same time. ...

That provision only applies where existing equipment is being replaced. It does not apply if you are installing additional equipment.