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As a lad many items which were three phase were marked 440 volt but since becoming an electrician it has been 415 and then 400 volt.
Since the volts are given as single phase I would assume:-
Single - Three
220 - 381
230 - 398
240 - 416
250 - 433
255 - 442
Now it seem most likely 440 was maximum voltage 440.6337 is three phase voltage plus 6% from 240 and 438.2089 is three phase voltage plus 10% from 230 volt. It would make sense to quote highest voltage on a warning label. But only guessing.
So any one know why it was called 440 volt?
Since the volts are given as single phase I would assume:-
Single - Three
220 - 381
230 - 398
240 - 416
250 - 433
255 - 442
Now it seem most likely 440 was maximum voltage 440.6337 is three phase voltage plus 6% from 240 and 438.2089 is three phase voltage plus 10% from 230 volt. It would make sense to quote highest voltage on a warning label. But only guessing.
So any one know why it was called 440 volt?