Master Switch; Avionics Power Switch; Ammeter - Cessna 1980 182Q Pilot's Operating Handbook And Flight Manual

CESSNA
MODEL 182Q
SECTION 7
AIRPLANE
&
SYSTEMS DESCRIPTIONS
CAUTION
Prior to turning the master switch on or off, starting the
engine, or applying an external power source, the avionics
power switch, labeled A VIONICS POWER, should be
turned off to prevent any harmful transient voltage from
damaging the avionics equipment.
MASTER SWITCH
The master switch is a split-rocker type switch labeled MASTER, and
is ON in the up position and off in the down position. The right half of the
switch, labeled BAT, controls all electrical power to the airplane. The left
half, labeled ALT, controls the alternator.
Normally, both sides of the master switch should 1?e used simultane-
ously; however, the BAT side of the switch could be turned ON separately
to check equipment while on the ground. To check or use avionics
equipment or radios while on the ground, the avionics power switch must
be turned ON. The AL T side cif the switch, when placed in the off position,
removes the "alternator from the electrical system. With this switch in the
off position, the entire electrical load is placed on the battery. Continued
operation with the alternator switch in the off position will reduce battery
power low enough to open the battery contactor, remove powerfroIIl the
alternator field, and prevent alternator restart.
AVIONICS POWER SWITCH
Electrical power from the airplane primary bus to the avionics bus
(see figure 7-7) is controlled by a toggle switch/ circuit breaker labeled
A VIONICS POWER. The switch is located oil. the left side ofthe switch and
control panel and is ON in the up position and off in the down position. With
the switch in the off position, no electrical power will be applied to the
avionics equipment, regardless of the position of the master switch or the
individual equipment switches. The avionics power switch also functions
as a circuit breaker.
If
an electrical malfunction should occur and cause the
circuit breaker to open, electrical power to the avionics equipment will be
interrupted and the switch will automatically move to the off pOSition.
If
this occurs, allow the circuit breaker to cool approximately two minutes
before placing the switch in the ON position again.
If
the circuit breaker
opens again, do not reset it. The a vionics power switch should be placed in
the off position prior to turning the master switch ON or off, starting the
engine, or applying an external power source, and may be utilized in place
of the individual avionics equipment switches.
AMMETER
The ammeter. located between the fuel gages, indicates the amount of
1 October 1979 7-27