3 phase 11 and 22kw - Current in Each Phase??

[SUNRAY]

When designing motor control panels I work on the basis of; power/230/2 = 22000/250/2 which simplifies as 22000 x 2 and comes out as ~44A basis for OCPD and wiring.

 

[JohnW2]

That's correct for supply at 400V phase-phase, which wasn't specified.

If, as seems to be the case, you're wanting to be pedantic, that statement is not strictly true. It would be 'correct' for a supply at (230 x √3) volts, which is about 398.37 V.

Kind Regards, John

 

[fixitflav]

If, as seems to be the case, you're wanting to be pedantic, that statement is not strictly true. It would be 'correct' for a supply at (230 x √3) volts, which is about 398.37 V.

Kind Regards, John

Not sure what you're getting at. I was just saying the voltage is needed to calculate the current (OK I accept the forum is Electrics UK, but it might possibly be 230 volt).

It's irrelevant whether you say 400 volt 3-phase, 400/√3 1-phase or 230 volt 1-phase, 230*√3 3-phase, they're only nominal figures. I believe it changed from 415/240 volt to 400/230 to be same as the continent, but with a +-5% tolerance, so 415/240 which is within the range. Though nothing needed to change, last time I checked, mine was 239 volt.

 

[JohnW2]

Not sure what you're getting at. I was just saying the voltage is needed to calculate the current

Fair enough. I thought you were saying that thee calculation using 230V )phase-neutral) was only correct if the supply was 400V phase-to-phase, which I took to bee a quibble about the numbers.,

(OK I accept the forum is Electrics UK, but it might possibly be 230 volt).

Again, fair enough, but I'm not sure that anywhere in the world has supplies with 230V phase-phase (i.e. about 133V phase-neutral), do they?

Kind Regards, John

 

[fixitflav]

but I'm not sure that anywhere in the world has supplies with 230V phase-phase (i.e. about 133V phase-neutral), do they?

Agreed, as you say it's highly unlikely, but strange things happen

 

[JohnW2]

Agreed, as you say it's highly unlikely, but strange things happen

I can't argue with that, but the fact that that is 'highly unlikley' combined with the fact that (as you have observed) this is an "Electrics UK" forum, I really can't see that anyone reading this thread would think other than that what was being referred to was a ('standard' oin thee UK) 230/400V 3-phase supply

Kind Regards, John

 

[fixitflav]

I can't argue with that, but the fact that that is 'highly unlikley' combined with the fact that (as you have observed) this is an "Electrics UK" forum, I really can't see that anyone reading this thread would think other than that what was being referred to was a ('standard' oin thee UK) 230/400V 3-phase supply

Kind Regards, John

OK

 

[Risteard]

Not sure what you're getting at. I was just saying the voltage is needed to calculate the current (OK I accept the forum is Electrics UK, but it might possibly be 230 volt).

It's irrelevant whether you say 400 volt 3-phase, 400/√3 1-phase or 230 volt 1-phase, 230*√3 3-phase, they're only nominal figures. I believe it changed from 415/240 volt to 400/230 to be same as the continent, but with a +-5% tolerance, so 415/240 which is within the range. Though nothing needed to change, last time I checked, mine was 239 volt.

+10%/-6%.

 

[fixitflav]

+10%/-6%.

Thanks, I wasn't sure about the %ages