A320 Emergency Electric Power Panel

MAN ON pb (guarded)

AUTO : When the following conditions are met:

  • AC BUS 1 is not electrically supplied, and
  • AC BUS 2 is not electrically supplied, and
  • Aircraft speed is greater than 100 kt.
    • The RAT extends, and
    • The blue hydraulic system drives the emergency generator.

As soon as the emergency generator electrical parameters are within tolerance the emergency generator is connected to the aircraft network.

Pressed : This selects manual RAT extension. Emergency generator coupling occurs 3 s after the RAT supplies the emergency generator.

FAULT light

This light comes on red if the emergency generator is not supplying power when AC BUS 1 and AC BUS 2 are not powered.

EMER GEN TEST pb (guarded)

Pressed and held:

  • If AC NORMAL BUSES are supplied:
    • The EMER GEN is driven hydraulically if the blue electric pump is running. The AC ESS BUS and the DC ESS BUS are connected to the emergency generator. (The DC ESS SHED and AC ESS SHED buses are not powered.) 
    • ECAM displays the ELEC page automatically (only on the ground). 
  • If only the batteries supply the aircraft:
    • The static inverter powers the AC ESS BUS.


  • OFF : GEN 1 line contactor opens. The AC BUS 1 channel is supplied from GEN 2 through bus tie contactors. This is used for smoked drill. 
  • SMOKE light : The amber light comes on when smoke is detected in the avionics ventilation duct.