Technical data

13773-001
24-50
Page 2 30 Nov 2000
(1) BAT & ALT Master Switches
Note: Prior to engine start-up, the pilot must activate only the BAT 2 switch to verify that
BAT 2 properly energizes the electrical loads powered by the ESSENTIAL Bus
and that BAT 2 has proper voltage. The voltage reading must be taken from the
combination Volt and Ampere meter mounted on the right instrument panel.
Use BAT 1 for suppling electrical power to the avionics system when performing
general servicing tests.
The rocker type electrical system MASTER switches are ON in the up position and off in the
down position. The left battery switches, labeled BAT 1 and BAT 2, control all electrical power to
the airplane. The right switches, labeled ALT 1 and ALT 2, control the corresponding alternator.
Normally, all master switches will be on. However, the BAT 1 switch can 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. Positioning the ALT 1 and ALT 2
switch to the off position isolates the alternators from the electrical system and the entire electri-
cal load is placed on the batteries.
Note: Continued operation with the alternator switch off will reduce battery power low
enough to open the battery relay, remove power from the alternator field, and pre-
vent alternator restart.
(2) Avionics Power Switch
A rocker switch, labeled AVIONICS, controls electrical power from the airplane primary bus to
the avionics bus. The switch is located next to the ALT 1, ALT 2, BAT 1, and BAT 2 Master
switches and is ON in the up position and off in the down position. Typically, the Avionics Power
Switch is used to energize or de-energize all avionics on the Avionics Non-essential and Avion-
ics Essential buses simultaneously. 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 individ-
ual equipment switches. The AVIONICS switch should be placed in the off position prior to turn-
ing the master switch ON or off, starting the engine, or applying an external power source.
The airplane has two different types of circuit protection devices. Each circuit has an electrical
protective device, with the exception of the starter motor. A 5-amp clock fuse is located in the
MCU and the push-pull type circuit breakers are all located in the cabin area. The fuses are not
replaceable during flight.
C. Transmission Wire
Power is routed throughout most of the aircraft with MIL-W-22759/16 teflon coated wires. These wires
have a 150° C rating. Joints made in wires are covered with polyolefin heat shrink material, or are
joined using a solder sleeve. In the engine compartment, all power wire terminal ring ends are covered
with a silicon boot. Rubber, nylon, or teflon grommets protect the wires from chafing where the wires
pass through materials that could cause wear.