is the Industrial unit supply man enough?

[bigfoots]

Learn how to make beer, at no time will all three mash tuns be on line at the same time.

BTW the best way to heat the wort is with a spiralled hot water coil fed from a domestic gas boiler. Steady gentle heat doesn’t burn the solids in the wort.
The heat from an immersion heater is too intense. It will caramelise the wort around the elements. If you want a dark beer, this isn’t the way to do it

Not that I know anything about beer.

I did suggest using gas as he already have on the premises but being a cheap skate he went for the cheaper option ( about £2000 less) of immersions but it will be more expensive in the long run with running cost on electric