single phase and 3 phase

[i=p/u]

Q1.in most domestics its 230v and 100A main fuse. is there a limit on how many amps can be drawn when on 230v??????? could there be 500A drawn if cables are large enough


Q2. as with 3phase 400v is there a limit on how many amps can be drawn???

maybe stupid question but just thinking , yas know me

thanks

 

[Johnny-G]

Cable sizing apart, wouldn't PFC be the limiting factor?

 

[somersetsparks]

Hi mate, working for the DNO, I have never seen a single phase supply more then 100a. Normally If a customer needs more supply they get another phase or 3 phase taking it up 2 300a accross 3 phases.

In theory I suppose you could but most cables and switchgear are designed for 100A, makes it easier for balancing the phases as well i suppose.

As for 3 phase, no limit, although most large industrial customers are metered at 11kv and have there own transformer/ 11kv network.

Some places can be metered at 33kv!

 

[i=p/u]

i understand pfc in single phase would limit it.

so in 3phase more less as much as you want as long as you balance out.. how close does the balancing have to be????

 

[somersetsparks]

Yes three phase is as much as you want, but like I said, Most large places have there own 11kv transformer and some have there own 11kv ring supplying panels in different buildings. balancing doesn't have to be spot on, you generally find in industrial situations its reasonably easy, a lot of loads are three phase anyway, its just lighting and sockets to balance, I ususally balance roughly first then use a clamp meter when a place is running normally. then jiggle the loads about a bit, although you have to be carefull not to make 2 points with touching distance on different phases ideally. Or the place ends up plastered in 400v stickers!