What size OCPD for 2 motors (200hp, 20hp)?

[kwired]

No, not at all. Only 2 motors will be added to this panelboard potentially: a 200hp motor and a 20hp motor. The other (2) motors are going in a different area of the facility and will not be connected at all to the 800a existing panelboard. In my OP, I suggested that we will be building a new service due to the lack of available power in that area.

If this second service is in a different area of same building as the original service you will have issues with multiple services to a building, better read up on art 230 part I before going ahead with this and maybe even get blessing from AHJ if you still want to go with it.

 

[carryyourbooks]

First things first, how are these motors starting? Starter, soft start, etc? Or does this machine come with a large control cabinet you simply hit with a feeder, a single point connection?

I don't have this information yet.

If this second service is in a different area of same building as the original service you will have issues with multiple services to a building, better read up on art 230 part I before going ahead with this and maybe even get blessing from AHJ if you still want to go with it.

We are in converstaion with the local utility on this part.

 

[Cow]

I don't have this information yet.

I wouldn't be calculating anything until I knew this information.

 

[kwired]

I don't have this information yet.




We are in converstaion with the local utility on this part.

Local utility will often provide you whatever you want and they don't enforce NEC, art 230.2 in general only allows one service to one building - can have up to six disconnecting means on that service but they must be grouped at one location.

When you have more then one voltage, number of phases, etc. there are exceptions, there are also exceptions for really large service requirements - but 800 amps is not deemed to be excessively large in very many instances. It is just barely starting to become large if the service were 120/240 single phase.