Electrical Engineering

Electronics Engineering

Electrical Wiring

# Why is 1 phase 240 volts and 3 phase 415 volts?

## Answer

###### Wiki User

###### 02/21/2015

In a three-phase, star- (or wye-) connected, system the line voltage (line-to-line voltage) is 1.732 (or the square-root of 3) times the phase voltage (line-to-neutral voltage). The reason for this is that a line voltage is the vectorial sum (not algebraic sum) of two phase voltages displaced from each other at 60 degrees.

These days, incidentally, the UK's *nominal* phase voltage
is 230 V, and its corresponding line voltage is 400 V.

## Related Questions

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Yes,
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415 V / root(3) = 239.6 Volts
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<<>>
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will both give you the correct answer. It is important to note
these values are RMS, not 0 - peak voltages, but this may be beyond
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A single phase 600 to 240 Volt transformer using two phases of
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=======================
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stator or bad connections to the stator. I'm not too familiar with
this exact model and what is between, if anything, the stator and
240 output. So someone else may be able to offer more assistance on
the in between.
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