Delta Secondary-Line to Neutral Relationship

[bbleiler]

What is the line to neutral mathematical relationship in a delta connected transformer secondary? As in, why is the "wild leg" voltage 208 volts, when the line to line voltage is 240 volts?

 

[RickOzone]

A delta connected secondary of a transformer does not have a neutral connection. Therefore there is no mathmatical relationship. Each of the phases is floating with respect to the neutral. If it where a Y connected, then the phase to neutral voltage would be Voltage Line to line / Square root(2.

 

[brennaj]

RickoZone - It is the square root of 3 - not 2, in your formula.

 

[47gandalf]

The 208 V comes from taking line to line (240 V) and multiplying by the sine of 120 degrees, i.e. the phasor angle between the three phases. My calculator gives 207.85 V as the actual value, rounded easily to 208.