Systems Guide

A318/A319/A320/A321
Professional
SYSTEMS
Systems guide
Vol
4
04-03-35
11 July 2018
advised to either connect external power of power up the APU to avoid your aircraft going cold and dead
unexpectedly.
PRIORITY LOGIC
The priority logic determines which source is used. When that source is lost the system will automatically
switch to the next available source.
1. Engine Generators
2. External Power
3. APU Generator
4. Ram Air Turbine (not simulated)
5. Batteries
For example, if the aircraft is run from APU generator and EXT PWR comes online the system will
automatically switch to EXT POWER but when engine generators come online they will be used.
GROUND POWER
Using the GROUND SERVICES menu on the right MCDU it
is possible to display a Ground Power Unit and to actually
let it supply the electrical power.
• EXT. POWER GPU: will activate ground power
and will show a Ground Power Unit
• EXT. POWER: will activate ground power but will
not show the Ground Power Unit (use this one in
combination with GSX)
ECAM ELEC SYSTEM DISPLAYS
The ECAM ELEC pages show the configuration of the electrical system and the relevant values of all
systems.
• The battery indications (BAT 1 & BAT 2) normally appear white but will show in amber if voltage
drops below 25 volt. Voltage and Amperage is shown. Connection lines or arrows between the
battery and the DC BUS icon show if the batteries are connected, discharging or charging.