KVA to amps help

[geordie]

Have got a new supply going in and have been told its 300KVA 3 phase now if i have worked it out correct is comes in a 433 amps which going by the size of the places i would expect to be per phase. Which i take it would be fused down to 400 amps by the DNO

 

[Guest55]

are you telling us or asking us ? ;-)

yeah 400A per phase is a standard dno supply size.

 

[ImpededLoop]

I'd agree, 400A 3 phase supply.

 

[Knobhead]

You’re right except for one thing, it won’t be 400V. It’ll still be fused at 400A

@433V it works out at spot on 400A

 

[geordie]

Thanks Guys always worth double checking things

 

[Guest55]

grow an awful lot of weed with that much power on tap !

oops , wrong forum :-D

 

[Darkwood]

Quick ball park sum for it is:-
3PH is Amps = Kva / 0.73
3PH Kva = Amps x 0.73

1PH Phase use 0.25 instead.

 

[telectrix]

is rtrhat 2.5 th successful propportoin of the plasnts thast grow inro maturity>?

 

[telectrix]

oooww.ps. ale is typring. bewweet shut ip. n

 

[atm84]

Quick ball park sum for it is:-
3PH is Amps = Kva / 0.73
3PH Kva = Amps x 0.73

1PH Phase use 0.25 instead.

Yes I agree as a quick ball park but a much more accurate figure is say 200kVA:

200,000/ 692 = 289 amps per phase

 

[Knobhead]

That’s based on the mythical 400V whereas a DNO transformer will be 433V and its rated current output will be based on that.

100KVA=133.3333333333333333333333333A

Not that it’ll make any odds, they’ll just bung a fuse in that’s the next size up.

 

[atm84]

Since when did a DNO transformer work at 433v?

 

[Knobhead]

Since when did a DNO transformer work at 433v?

For the last 80+ years.

Measure the voltage at your house. I’ll put money on it not being 230V but nearer 250V.

I assume you’ve not been an electrician for long.

 

[Simonslimline]

For the last 80+ years.

Measure the voltage at your house. I’ll put money on it not being 230V but nearer 250V.

I assume you’ve not been an electrician for long.

248volts last time i measured it in my flat.

 

[atm84]

Since when did a DNO transformer work at 433v?

For the last 80+ years.

Measure the voltage at your house. I’ll put money on it not being 230V but nearer 250V.

I assume you’ve not been an electrician for long.

Haha always has to have a dig don't you? What relevance is that. For your info I was a electrician for over 8 years before moving onto bigger and better things.

 

[telectrix]

so, bigger and better things than a spark? when yo rulle the world? seig heil?

 

[davesparks]

Since when did a DNO transformer work at 433v?

For about the same amount of time they have been 250v

 

[Darkwood]

Haha always has to have a dig don't you? What relevance is that. For your info I was a electrician for over 8 years before moving onto bigger and better things.

Go on then, entertain us! What bigger and better things could their possibly be ?????

 

[Guest55]

Go on then, entertain us! What bigger and better things could their possibly be ?????

maybe............

 

[Knobhead]

I await atm84’s reply with baited breath.

He’s probably be better off burger flipping, all he has to do is blithely follow the instructions on the pack. He can’t mess the chips up, I know what was done to them before they reach the outlet.


atm84, eight years in the trade and you haven’t yet worked out that 400V is a work of fiction written jointly by the EU and the IET. In the UK it is totally impractical due to the massive installed infrastructure based on 433V.
It takes but a stroke of the pen to deem 400V as the public supply voltage. The engineering side realized it’s impossible and just ignored the directive. A classic case of it’s my bat and ball, I make the rules.

Some of the lads know of my experiments of lowering the voltage on a 80,000KVA system to 400V. It ended in total disaster and I put the voltage back to 433V pronto.