Trouble Shooting; Timer Test; Slip Ring Alignment - Cessna T182 Series Service Manual

MODEL 182 & T182 SERIES SERVICE MANUAL
14-66. TROUBLE SHOOTING.
NOTE
The propeller anti-ice ammeter may be used while trouble
shooting the system. The ammeter needle should rest
within the shaded band except for "flickers" approximately
20 seconds apart, as the step switch of the timer operates.
The ammeter will also reflect a bad connection or open
circuit by reading below normal or zero. A high reading
indicates a short circuit.
TROUBLE
PROBABLE CAUSE REMEDY
ELEMENTS DO NOT
Circuit breaker out Reset circuit breaker. If it
HEAT.
or defective, pops out again, determine
cause and correct. Replace
defective parts.
Defective wiring.
Repair or replace wiring.
Defective switch.
Replace switch.
Defective timer.
Replace timer.
Defective brush-to-
Check alignment. Replace
slip ring connection.
defective parts.
SOME ELEMENTS DO
Incorrect wiring. Correct wiring.
NOT HEAT.
Defective wiring. Repair or replace wiring.
Defective wiring. Replace timer.
Defective brush-to- Check alignment.
Replace
slip ring connection.
defective parts.
Defective element.
Replace element.
CYCLING SEQUENCE
Crossed connections
Correct wiring.
NOT CORRECT OR
NOT CYCLING.
Defective timer.
Replace timer.
RAPID BRUSH WEAR.
Brush block or slip
Align properly.
FREQUENT BREAKAGE.
ring out of alignment.
SCREECHING OR
CHATTERING.
14-67.
TIMER TEST.
When correctness of the cycling sequence is estab-
a.
Remove connector plug of wire harness from
lished, turn propeller de-ice switch off at the begin-
timer and jump power input socket of wire harness
ning of one of the on-time periods, and record the
to timer input pins.
(Refer to chart following this
number of the pin at which the voltage supply is pre-
paragraph for pin identification.)
sent.
b. Jump timer ground pin to ground.
c.
Turn on de-icing system.
TIMER P/N ..............
C40171
d.
Check timer operation per the chart. (Use a
POWER INPUT PIN .......... 1 (24VDC)
voltmeter.)
GROUND PIN
.......... . 5 (24VDC)
e.
Check volts to ground in each case. If engine is
OUTPUT SEQUENCE 2 sequences, 30 seconds each
not running. and auxiliary power is not used, voltage (TIME)
will be battery voltage and cycle time may be slightly
TIME REPEAT CYCLE TIME (SECONDS) ..
..
60
longer than indicated.
f.
Hold voltmeter probe on pin until voltage drops 14-68.
SLIP RING ALIGNMENT. After installation.
to 0.
Move probe to next pin in the sequence shown
the slip ring assembly must be checked for run-out,
in the chart.
Check voltage at each pin in sequence.
and adjustments made. if necessary.
14-29