Cable and breaker size?

JohnP1 · Nov 23, 2011

Hi all im new to this forum and im looking for some help.
I need a 63kw 3 phase supply to run a machine in a commercial building,
the cable run is 25 or 30 meters roughly.
I was going to run in a 35 square cable to the machine and there is an existing isolation breaker at the main mcc with 3 x 63amp fuses in it,
the tails feeding it look like 50 square and there is no rating on the switch!
I should be well covered if i change the fuses to 100amp per phase?

Cheers,
John

johnboy6083 · Nov 23, 2011

It seems like you will be ok as long as you don't have to derate the cable. Havent got vd figures to hand. Will Disconnection times be met?

JohnP1 · Nov 23, 2011

Well johnboy, there will be like a suboard at the machine feeding all appliance's off of it.
I was just asked to bring a supply to the unit itself, everything around the unit is pre wired to i assume the correct standards with all the correct rcd's/mcb's etc will be in place. I thought i was going to get a couple of weeks work out of it but unfortuanatley not!