Apu Normal Shutdown - BOMBARDIER Challenger 601-3A CL-600-2B16 Pilot Training Manual

On aircraft with SB 601-0418 and serial num-
bers 5135 and subsequent, a backup battery is
provided to power the APU ECU during cold
weather starts. While the APU ECU is pow-
ered from the battery bus, it also receives
power from the avionics IRS No. 2 system's
backup battery (Figure 6-8). During cold
weather APU starts, the output level from the
aircraft main battery might not be sufficiently
high to maintain ECU operation. The backup
battery will ensure a successful start.
AUXILIARY BATTERY
IRS
1
APU BATT/CHARGER FAIL
Figure 6-8. Auxiliary Battery Panel
(SB 601-0418)

APU NORMAL SHUTDOWN

The APU is normally shut down by:
1. First turning off the APU generator
switch (Figure 6-9) and, without fur-
ther delay,
2. Push the START-STOP switchlight
( F i g u r e 6 - 5 ) . T h e A P U s p o o l d ow n
should be monitored on the rpm indica-
tor until it reaches zero. The spooldown
should be smooth.
3. Press out APU BLEED AIR switchlight.
4. Press out APU POWER FUEL ON/OFF
switchlight.
IRS IRS
2 3
FOR TRAINING PURPOSES ONLY
FlightSafety Canada
CL-600-2B16 PILOT TRAINING MANUAL
Figure 6-9. Electrical Control Panel
Lt é e
Lt d .
CL 601-3A/R 6-9