Dam that's cheep! $400 to upgrade the service is very cheep. I see that your planning on running a second panel instead of one 400 amp panel. Still that must be one cheep panel, breakers, wire, upgraded grounding conductor, service laterals, conduit, heck here they get $40 for one stick of 2" emt, etc... and the labor too wow I need to move to where ever you live!
Some places they will "upgrade" you to a commercial account to go to 400 amp service. Then they do charge you more for the additional KVA capacity. Here they will hang any transformers I want to pay for on the pole but it bumps my base rate up rather fast if I need a larger bank of them. Also here I get a KVA charge for any thing over 75kva draw (for more than 15 min). Do that ONE time in the month and it's an automatic $750 charge for the month PLUS the KW charge for the amount used... YMMV
Well you can pull a lot more than 200 amps before the cheep home type main breakers pop off, but you can only do it for a short time. Like when you try to start your 7.5 hp phase converter up (if it's a HD 7.5 made from a
15hp 3 phase motor) and it pulls 120 amps for a few seconds through a 50amp breaker. When I start my 20 hp Air compressor it whops the line for 135amps @ 480volts 3 phase for the 3-4 seconds it takes to spin it up, but it's only for a short time and the $400 60 amp breaker handles it fine (The 30 didn't like it much though:-)Well if they will do the upgrade for free ( the power co) and not charge you any more, you can't beat that deal with a stick!
William....