The AC essential bus needs to get power from somewhere right?
Power from the batteries is DC. It needs to be AC..
The AC Static Inverter takes DC power and changes it to AC to power the AC ESS BUS.
A direct quote from the FCOM..
STATIC INVERTER
A static inverter transforms DC power from Battery 1 into one KVA of single-phase 115 V 400 Hz AC power, which is then supplied to part of the AC essential bus. When the aircraft speed is above 50 kt, the inverter is automatically activated, if nothing but the batteries are supplying electrical power to the aircraft, regardless of the BAT 1 and BAT 2 pushbutton positions.
When the aircraft speed is below 50 kt, the inverter is activated, if nothing but the batteries are supplying electrical power to the aircraft, and the BAT 1 and BAT 2 pushbuttons are both on at auto.
Philtowns...if you hold a frozen ATPL as your profile suggest.. surely you would have studied this and be a little less confused?
But then again, maybe it wasn't a question on the Bristol G/S database
