I have customer that needs to upgrade his service from 800Amps to 1200Amps. He currently has a 120/240V 3 phase system and a 120/240V System With 2 separate Meters. I am advising that he upgrade and go to a 1200Amp 480V 3 phase system and transform down for existing loads. Will he save any costs on his electric bill over time with a single serevice at 480/277V? If so what approx.

I small apples and oranges. You can't compare. Now if you compaed kVA to kVA we're getting somewhere.

Only the, can you start to determine cost-effeciveness.

Energy is Energy. You loose when your power factor goes nuts because of utility penalties.

You may be able to ditch jut about all of it unless he needs 240 and go 480/277 3p, 208 3p and 120 1p.

Usually you save on copper costs by going to a higher voltage.

What kind of loads do we have now and what kind od additional koads are proposed/ What' the kVA requrements of both.

Yea, changing to a single service might help. For one, there would be only one utility charge.

I doubt your lighting has universal ballasts, so changing lighting to 277 would not be feasible.

You have to look at what you can reuse or is this going to be a hodge podge kind of thing.

You need to look primarily at the additional loads planned. If it's a 7000 HP chiller or 25, 1000W kilns.

You need to look to see if your motors will like 208V rather than 240.

Is he a candidate for primary distribution?

Above all compare apples to apples and do a load analysis. This means knowing what's connected.

For instance, there are advantages of doing a floor by floor distribution and there are advantages of using a transformer and load center in a machine shop.

Electricity you won't save. You may have a payback. It may be easier to troubleshoot. It might be time for an upgrade.

I've asked that this tread be moved to Electrical & Lighting so we can get better input from our resident Electricians even though it's in the major category "Home and Garden". It's not your fault it ended up here.