A320 Electrical System / Sources

Dear All,

The A320 has alot of electrical sources. They are as follow:

1- Two AC main buses. Each AC bus is energized from an IDG - Integrated Driven Generator - installed on each engine. The output values are: 115VAC / 90 KVA / Frequency 400 Hz.

2- One main AC bus is feeding something called essential bus and essential shed bus. The shed bus is connected to the equipment at which is important for the safety of the aircraft when buses are lost. When the main AC bus failed, then the another AC bus can be connected to the essential bus to feed it instead of the faulty one either automatic transfer or manual by push button when the auto logic fails.

3- The AC essential bus also can be fed by the emergency generator. This generator is hydraulically powered to give output electrical AC power to feed the AC essential bus. The generator is hydraulically powered by hydraulic pressurized either from the related hydraulic system if the blue hydraulic system pump is operative or by the RAT - Ram Air Turbine -. Note that the RAT can only turn at specific minimum speed on some A320 its 150 KNOTS on another A320 it is 100 knots or until the flaps slats extended.

4- When the RAT stop working, the AC essential bus will be fed from the batteries through a static inverter that will convert the 28 VDC into 115 VAC. So as you can see, the major equipment are connected with essential buses (AC and DC through essential transformer). This essential buses are always fed either from IDG, APU generator, CSM/G - Emergency Generator - using the RAT, and or static inverter. This will give the electrical system a very very high redundancy.

Thanks for AIRBUS.

B.Regards
Ayman Shak'ah
Licensed Aircraft Maint. Engineer