FlightSafety Canada
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CL-600-2B16 PILOT TRAINING MANUAL
CL 601-3A/R
8-7
FOR TRAINING PURPOSES ONLY
APU FIRE EXTINGUISHING
The APU fire-extinguishing system operates
in a manner similar to that of the engine sys-
tem and includes a Firex bottle, an APU FIRE
switchlight, a BOTTLE ARMED switchlight,
and a split-legend LO PRESS light/SQUIB
test switchlight.
APU Firex Bottle
This bottle is installed adjacent to the APU in
the rear equipment bay.
The bottle is a 60-cubic-inch container with
a single electrically operated discharge port,
a thermal discharge port, an indicator, and a
pressure switch.
As with the engine system, the bottle is charged
with Halon 1301 fire-extinguishing agent and
pressurized by dry nitrogen at 600 to 625 psi.
The electrically operated port is connected by tub-
ing to the APU compartment and contains a squib
(with dual-firing cartridges for redundancy).
The thermal discharge port operates when the
pressure in the bottle exceeds 1,400 psi and dis-
charges the bottle contents into the area sur-
rounding the bottle installation.
The indicator displays bottle pressure in the
range of from 0 through 1,500 psi.
The pressure switch in the bottle operates at
275 psi to indicate that the bottle pressure is
too low to be useful.
As with the engine bottles, once discharged,
the APU Firex bottle must be replaced.
Figure 8-6 illustrates the APU fire-extinguish-
ing system.
ENG FIREX
BOTTLE
ENG FIREX
BOTTLE
Figure 8-5. Engine Fire-Extinguishing System