can we save with a simple 3 phase 120/208 installation vs 3 phase + single phase

Hello,

i need few advises as i'm drawing plans for my new commercial installation.

We currently have 400amp 3 phase at 240v delta 3W + single phase 200 amp at 120/240v in one building, thus two meters.

We need to wire a warehouse and a shed on the same parcel but separated from the main building.

The warehouse would need 3 phase 400 amp at 120/208V + single phase 200 amp at 120/240V (for domestic applications), and the shed could have a 3 phase 40 amp sub panel from the warehouse and another single phase sub panel for light equipment (lighting, alarm, etc)

My question is, as this configuration would involve upgrading to a 3 phase 800amp 120/208V 4W and 400 amp at 120/240v installation,

wouldn't it be easier and more economical to draw single phase out of 1200amp 120/208V 4W splitted in 2x 600 amp load centers when needed and thus only install 3 phase distribution panels?

I have to stress that we subsequently plan to install a solar system, and i have no idea if this will be compatible with that configuration.

Any advise or opinion is welcome!
Thanks

 

If you have no 240 volt loads (single or 3 phase) then you can have a 120/208 volt 3 phase system serve everything -- 208 volt 3 phase loads and 120 volt single phase loads (and also 208 volt single phase loads).

You'll have to check if the power company offers 120/208 volt 3 phase.

There may or may not be complications rewiring all of the 3 phase panels to have a neutral for the 120 volt branch circuits.

 

What are the loads on the 3-phase, 3-wire, 240 volt Delta system ?; are they mostly 3-phase , 240 volt motors?

Is it possible the Utilty Co can provide a seperate Service for the warehouse?;you may need to leave the existing Delta system intact.

 

Why do you need so much power for a simple warehouse, how big is it? Is there production machinery that requires all that power? You don't need a separate single phase service if your 3-phase service is 120/208V 3p4W. This service would provide your 120 volt needs. Your 240 volt needs would be served by 208 volts.

Can you provide some load information?