Kva! How Many Amps

[johnnymac]

Hi can anyone tell me how many amps is equal to 25 KVA on a 3 phase supply please?

 

[Marvo]

Can you clarify? Are you asking how many amps per phase...as in what size mcb you would might need? Is the supply 400v without neutral or is it 3-phase with neutral?

 

[johnnymac]

its 3 phase and neutral.

 

[ProDave]

36.2A per phase, assuming a balanced load. And it goes without saying assuming 400V. Also assuming a unity power factor.

 

[johnnymac]

its a new 3 phase supply in to a building for a cafe, 36 amps per phase seems low??? Its going to have fryers,dish washer grills etc

 

[Marvo]

The fryers alone will probably require a larger supply than this. It's way undersized.

 

[ProDave]

What's the REAL question you are asking?

I assume you are getting a new supply offered, and the supply Co have offered you a 25KVA supply?

If you are getting a new supply, it's up to YOU to work out the demand ans specify the KVA rating of the supply that you want.

Don't forget diversity when doing your sums.

 

[bryanh]

Unless I am mistaken KVA is just kilovolt-amps, or volts times amps divided by 1000, so 230v x 100amps÷1000 =23KVA without taking power factor into account and that 230volts is your standard incoming supply in the UK

 

[wozz]

where did the 25Kva come from in the first place? Are you sure that isnt per phase?

 

[ProDave]

Unless I am mistaken KVA is just kilovolt-amps, or volts times amps divided by 1000, so 230v x 100amps÷1000 =23KVA without taking power factor into account and that 230volts is your standard incoming supply in the UK

but he's talking about a 3 phase supply, which as I already stated works out at 36 amps per phase. If you were really able to draw 100A per phase continuously, then it would be a 75KVA feed.