Eurocopter AS 350 83 Flight Manual page 262

COMPLEMENTARY FLIGHT MANUAL
.SECTION 7.9
1 -OC POWER SYSTEM
1~
DC power is provided by a starter-generator and by a 15 ~-hr buffer-
mounted storage battery.
A second identical storage battery may be installed as optional equipment.
An external power receptacle on the R.H. side of the aircraft may be used
to supply the aircraft electrical system from a 28 VOC ground power unit.
.
The generator and the battery are coupled to the distribution bus by means
of line contactors, which can only close if the ground power unit is
disconnected.
2 EXTERNAL POWER CIRCUIT
The ground power unit is coupled at ,the primary distribution bus by means
of its contactor when the following conditions are met:
-electric power is available at the external power receptacle
-the "MASTER SW" pushbutton is released
-the "EXT PWR BATT" pushbutton is engaged.
The "GEN" and BATT" lights are illuminated.
The battery and the generator are isolated from the system until the
ground power unit is disconnected.
3 BATTERY CIRCUIT
The battery is coupled to the primary distribution bus by means of its
contactor when the following conditions are met :
.
-electric power is not available at the external power receptacle
-the "MASTER SW" pushbutton is released
-the "EXT PWR BATT" pushbutton is engaged.
The battery may be isolated from the aircraft power system either:
.manually using the "MASTER SW" and "EXT PWR BATT" switches,
.or automatically by connecting the ground power unit.
.
350 B3 7.9
97-40 Page 1