Distance from Panel to Subpanel

[mills trainer]

In a commercial application, I have an existing 4000 amp switchboard. I installed a 800 amp switch in this switchboard and installed 800 amp fuses in it. These feeders run approximately 300 ft to a MLO subpanel. This subpanel has nine 3 phase breakers in it that feed various loads. Is this allowable by code or do I need a main disconnecting means closer to the MLO subpanel? It is all in the same building.

 

[robert]

Re: Distance from Panel to Subpanel

Your install should be fine. In michigan that would fly all day as long as you compensated for voltage drop and your panel is rated 800amps.

 

[russ]

Re: Distance from Panel to Subpanel

Mills:

Roberts answer is correct.
You can see for your self at 408.16 2002 NEC or 384.16 1999.

Russ