Cessna 402B 1973 - Propeller Deice System; Propeller Deice: Normal Operation

NORI'IAt OPERAIION
To operate the
propeller
deice
system
proceed
as
follows:
(1)
Battery Switch
- ON.
(2)
Propeller
Deice Circuit
Breaker
- CHECK in.
(3)
Propeller
Deice
Switch
-
ON.
(4)
Ammeter
-
CHECK,
Periodic
fluctuation
(14
,to
f
A
Amps.
)
of
the
propeller
deice ammeter
pointer,
indicates
normal
operation of
the
deicing elements
of first one
propeller
then the
other.
NOTE
To
check
all the
heating
elements
of
both
propellers
and
the
deice
timer
for normal
operatiorl
the sys-
tem
must
be left
ON
for approximately
two to
two
and
one-half
minutes.
The
timer
directs current
to
the
propeller
boots
in cycles between
boot
elements and
between
propellers
in
the
following
sequence:
Heating Period
No. 1
- Outboard
Halves
-
right engine
blades.
Heating
Period
No.
2
- Inboard Halves
- right
engine blades.
Heating
Period
No.
3 -
Outboard
Halves
- left
engine
blades.
Heating
Period
No. 4 -
Inboard
Halves
-
left
engine
blades.
Each
heating period
lasts approximately
one-half
minute.
EMERGENCY
OPERAIION
Abnormal
operation
of
the
propeller
deice system is
indicated
by
the
circuit
breaker
popping
out,
or by
the
propeller
deice
switch
tripping to
the OFF
position.
Failure
of
the circuit breaker
or
switch
to stav reser
indicates
that
deiclng is impossible
for
the
propellers.
A
reading below
14
amperes
on
the
propeller
deice
ammeter
indicates
that
the
bL:ades
of
the
propeller
are
not
being
deiced uniformly.
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