FALCON 7X 02-24-10
CODDE 1 PAGE 3 / 8
DGT97831
ATA 24 – ELECTRICAL POWER
DESCRIPTION ISSUE 2
DASSAULT AVIATION Proprietary Data
NOTE
Very low-charged batteries cannot be connected to the buses,
as their contactors need at least 18 VDC to close.
As soon as one generator is connected, batteries are charging and flatten generator
electrical spikes.
The batteries are also used in case of main generators loss, during the RAT deployment and
additionally just before landing when low airspeed does not allow the RAT to provide
sufficient electrical power.
In flight, the batteries can provide electrical power for a load of 200 A for 7 minutes.
RAM AIR TURBINE
The Ram Air Turbine (RAT) system provides a non-time limited electrical power source 9kw
to the RH and LH Ess bus for continued safe flight and landing in case of:
- Loss of all three engines (automatic deployment),
- Loss of all three engine generators (automatic deployment),
- Loss of engine 2 generator and short on LH ESS bus (manual deployment),
- Loss of engine 2 generator and BUS TIE contactor failed open (manual deployment).
When operative, the RAT will charge the airplane batteries.
When the airplane speed is low (approach and landing), the RAT generator output voltage is
reduced, and batteries start providing power. In this manner both the RAT and batteries
power all the required airplane loads during this phase.
NOTE
A safety lock pin with a REMOVE PIN BEFORE FLIGHT flag is used
to preclude inadvertent deployment of the RAT on ground.
The RAT is fitted with a RAT generator heater that is powered during all phases of flight,
except when the RAT is deployed and in operation. The purpose of the heater is to prevent
moisture within the air gap of the generator from freezing.
When deployed, the RAT induces a moderate level of noise and vibration in the cockpit.
Once the RAT is deployed, it will have to be restowed on ground with a restow pump.
PMA
Two PMA (Permanent Magnet Alternator) driven by engines 1 and 2 provide an independent
source of power to the Primary Flight Control system.
Three PMA driven by each engine provide an independent source of AC power for their
respective EEC (Engine Electronic Controller).
