Hi guys,
I'm working in a new role which requires me to size SWA cable to feed sub boards which in turn supply EV chargers. I noticed on the jobs that have been done already they have used 50mm 4c and 70mm 4c to feed 3ph 250A main switches on the sub boards. Going by tables and calculators this should be a 95mm 4c swa minimum (to have enough CCC incase it reaches 250A). Is there something obvious I'm missing? Sorry if this seems a stupid question, I just don't have experience in this area and would like to see if anyone can clear it up for me.
I'm working in a new role which requires me to size SWA cable to feed sub boards which in turn supply EV chargers. I noticed on the jobs that have been done already they have used 50mm 4c and 70mm 4c to feed 3ph 250A main switches on the sub boards. Going by tables and calculators this should be a 95mm 4c swa minimum (to have enough CCC incase it reaches 250A). Is there something obvious I'm missing? Sorry if this seems a stupid question, I just don't have experience in this area and would like to see if anyone can clear it up for me.