The electrical power system is a 28 VDC electrical system supplied by the electrical power generation system and the electrical power distribution system.

The electrical power generation has the DC power sources that follow:

• 400 A DC generators, installed on the engines, which supply normal 28 VDC power to the aircraft electrical busses
• An identical 400 A DC generator, installed on the APU, which supplies alternative 28 VDC power
• Emergency power supplied by:
  

  • Two 44 Ah batteries (these batteries are also used for the auxiliary power unit (APU) start)
  • A third battery for the integrated standby instrument (ISI).

• External DC power that can be connected to the aircraft electrical busses when the aircraft is on the ground.

The power distribution includes a primary distribution system and a secondary distribution system. The power distribution is supplied through seven distribution boxes as follows:

• The primary power distribution is supplied by three (left, right, and APU) DC power centers (DCPCs)
• The secondary distribution is supplied by two (left and right) secondary power centers (SPCs), four junction boxes (JBs) and two (left and right) circuit breaker panels (CBPs).

The electrical control panel provides indication and manual control of the power sources via pushbutton annunciators (PBAs). System monitoring is provided by EICAS and the electrical synoptic display on the adaptive flight display (AFD). This power is provided by inverters.