I have a machine which is wired as 3 phase neutral and earth and is 15.1KW, there are no 415v components and all components are 230v, so effectively it is using 3 single phase circuits, however I have always carried out the circuit breaker calculation based on the 415V potential, I.E> 15120W divided by 415V =36.43 therefore I would fit a 40Amp 3 phase breaker, I have been told by the manufacturer that I have incorrectly calculated this and should divide this calculation by 3 to calculate the correct 3 phase breaker and i should fit a 12A 3 phase breaker, I am not convinced that this is correct but am now second guessing myself, can any one assist.
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What machine are you speaking of?
It is a Coffee machine
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Square root of 3, 1.732 to 3 decimal places
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How do you know the load is spread evenly ?
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per phase would be 21amps ,
15120W * 400 *1.732=21amps
15120W * 400 *1.732=21amps
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Hi - and I reckon you are right to be concerned, because their suggested breakers would seem suitable for about 8kW load, not 15kW.
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15kw in star configuration is the same as 3 x 5kw loads on separate 1ph supplies.
5kw /230v = 21.7A
15kw /400 / 1.732 =21.65A
if they are all running off a single phase supply then its 15kw / 230 =65.2A
the manufacturors instructions should have the supply requirement printed in them.
if they are wrong, then after you have advised them then its there problem???
5kw /230v = 21.7A
15kw /400 / 1.732 =21.65A
if they are all running off a single phase supply then its 15kw / 230 =65.2A
the manufacturors instructions should have the supply requirement printed in them.
if they are wrong, then after you have advised them then its there problem???
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