Cessna TURBO CENTURION T210M 1978 Pilot Operating Handbook page 173

SECTION 7 .
CESSNA
MODELT210M
AIRPLANE
&
SYSTEMS DESCRIPTIONS
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 also be
turned on. The ALT side of 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 power from the
alternator field, and prevent alternator restart.
AVIONICS POWER SWITCH
Electrical power from the airplane primary bus to the avionics bus
(see figure 7-9) is controlled by a rocker-type circuit breaker-switch
labeled A VN PWR. The switch is located on the left sidewall circuit breaker
panel and is ON in the forward position and OFF in the aft 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 approximately two minutes to cool
before placing the switch in the ON position again.
If
the circuit breaker
opens again, do not reset it. The avionics 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 indicates the flow of current, in amperes, from the
alternator to the battery or from the battery to the airplane electrical
system. When the engine is operating and the master switch is turned on,
,,---...,,_ the ammeter indicates the ch!l,rging rate applied to the battery. In the event
the alternator is not functioning or the electrical load exceeds the output of
the alternator, the ammeter indicates the battery discharge rate.
OVER-VOLTAGE SENSOR AND WARNING LIGHT
The airplane is equipped with an automatic over-voltage protection
system consisting of an over-voltage sensor behind the instrument panel
and a red warning light, labeled HIGH VOLTAGE, near the airspeed
indicator.
In the event an over-voltage condition occurs, the over-voltage sensor
automatically removes alternator field current and shuts down the alter-
7-37