Hey there,

I'm not an electrian, and didn't pay enough attention in physics in college...

The company I work for has just taken over new space that has an existing 3 phase mains. The distribution board has a 200 amp mains breaker, and then is broken out into a dozen 20 amp single phase circuits.

I assume it was standard wiring, splitting the three hot wires up evenly (I am assuming it's 4 wire).

The issue is that the building management company wants to charge for 600 amps. They claim that we can utilise 600 amps as it is right now (without changing any breakers, wiring, etc).

They are unwilling to meter and charge per kWh as we'd prefer.

My limited understanding of 3-phase is that while the physical cables might be capable of transporting the load, the breaker should still trip beyond 200 amps. Right?

Or does the breaker snap only if one of the legs exceeds 200 amps and you really can run 500+ amps?