
OPERATION
The sensing loops are connected in series and
will give a cockpit indication if they detect a
temperature in excess of 375°F in the pylon and
778°F around the engine jet pipe exhaust. (See
Figure 8-12.)
Whenever the temperature exceeds the trip
level, the overheat detection unit illuminates the
red OVHT light on the center instrument panel.
If an overheat occurs, the crew can reduce
power to lower the temperature. If that is un-
successful, the engine must be shut down to
prevent structural damage. When the temper-
ature is reduced below the trip level, the red
OVHT light extinguishes.
Should a loop become shorted, the overheat de-
tection unit illuminates the amber OVHT
WARN FAIL light. This also brings up the
flashing master caution lights and the engine
system light, indicating that a true overheat
cannot be detected.
TEST
Pressing the OVHT switchlight grounds the
loop as in the fire detection warning test. The
red OVHT light illuminates to indicate the
detection system is serviceable.
Pressing the OVHT WARN FAIL switchlight
grounds the loop also. This causes illumination
of the OVHT WARN FAIL light along with an
appropriate master caution system reaction.
FlightSafety Canada
L t é e
L t d .
CL-600-2B16 PILOT TRAINING MANUAL
CL 601-3A/R
8-15
FOR TRAINING PURPOSES ONLY
OVHT
OVHT
WARN
FAIL
OVHT
OVHT
WARN
FAIL
LEFT
RIGHT
PUSH TO TEST
ENGINE JET PIPE/PYLON
LEFT
JET PIPE
DETECTION
LOOP
LEFT
PYLON
DETECTION
LOOP
LOOP
MONITOR
OVERHEAT
RESISTOR
TRUE
OVHT
FLASHER
778
°
F
375
°
F
WARN
FAIL
WARN
FAIL
INHIBIT
POWER
SUPPLY
28 VDC
BATT BUS
RT CB-B179
LT-CB-B178
ENG JET
PIPE OVHT
LEFT OVERHEAT
DETECTION UNIT
MASTER
CAUTION
PRESS TO
RESET
ENGINE
Figure 8-12. Engine Jet Pipe/Pylon Overheat Detection System