Airbus Electrical generator question

[JIMBO01]

Hi, the airbus manual states that:

"Each generator can supply up to 90 KVA of power at 115 and 200v and 400 Hz"

Why is there two voltages (115 and 200v) and is there a relation to 3 phase AC?

[IFixPlanes]

... is there a relation to 3 phase AC?
Yes, Wikipedia (http://en.wikipedia.org/wiki/Three-phase_electric_power#Single-phase_loads) can help... ;)

[tvrao]

The generator is 3phase AC generator whose windings are wound on what is called star connection.So this will have 3phases called A,B,C and a neutral N which is at zero volts and connected to aircraft structure. when voltage is taken from anyone phase(A or B or C) and neutral N , then it is 115 Volts. This is called phase voltage Vph.This voltage is applied to majority of electrical circuits in the aircraft. If the voltage is taken between any two phase like A and B or B and C or C and A ,then it will be 200 Volts.It is called line to line voltageVL. This is type of connection is used in the aircraft Cockpit window heater in High heat mode.
From basic electrical theory of 3 phase alternating current(AC) generator :
Vph=Voltage between any phase and neutral=VL/Sq.root of 3
Thus if VL=200V ,you getVph=200/sq,root3=116 approx but taken as 115 normally
These voltages 115/200 are standard for any commercial passenger /freighter aircraft manufactured by either Boeing or Airbus.Of course not for A380 and 787.
The relation between line voltage and phase voltage is always same(Phase voltage approximately 0.58times line voltage)