480sparky, Thanks much for the pics...
as the saying goes...."worth a thousand words"
I threw those up because I knew I had them on my Photobucket page.
The individual loads on the feeders in the wireway post must be minimal
It's an old 10-unit apartment building. Gas stove in each units, central heat & hot water, no AC.
I took that image because the owners were wanting to abandon the old boiler and install baseboard heat in all the units. There was only 3 120v circuits going to each unit.
You can see the original 60a service conduits above the existing 200a (yes, only 200) disco on the right. I calculated an 800a service, (because by local codes, I would have to update all the units with bath & SABCs, AFCIs, TRs......) and by the time I got halfway through pricing the job, they decided not to proceed.