Service Upgrade

[billto]

We currently have a 480V/400A service to our site. We need to add a 250HP/480V (FLA=285) motor. The rest of the site has about 250HP of connected load with perhaps about 100HP of continuous load. This new motor will dictate that we need to upgrade the service to the site.

The new motor is driving a hammer-mill so the initial torque will be high. Probably use a soft-start or VFD.

Can anyone suggest what size of service we will need to upgrade to...

 

[iwire]

Bill, you have no other loads?

No lighting?

No heating or cooling?

No receptacles?

 

[billto]

Other loads are minimal...
Area lighting is next to nothing, no HVAC, building lighting, recept. & misc loads are fed from a 75kVA 3ph xfmr (fairly well balanced and very lightly loaded). In other words, the 250HP motor will be by far the largest load.