7-14
ENSTROM 280FX OPERATOR’S MANUAL
Rev.
12
Report No. 28-AC-020
Dec 3/18
by the 4-digit numeric display on the GEM 610 or the 9-
segment alphanumeric display on the EDM 700. Refer to
the applicable engine monitor pilot’s guide for accessing
the OAT parameter display. S/N 2146 and prior
helicopters are also equipped with a direct reading OAT
instrument located in the top of the cabin.
7-13. Electrical Power Supply System
1. Direct Current Power System
The basic power supply system is either a 12-volt or a
28-volt direct current system, with a negative ground to
the helicopter structure. A belt-driven 70-amp alternator
is located on the aft part of the engine. On early
production helicopters with a 12-volt system, the 12-volt
battery is located in the right-hand side of the pilot’s
compartment and serves as a stand-by power source to
supply power to the system when the alternator is
inoperative. If the helicopter has a 28-volt system or is a
later production helicopter with a 12-volt system, the 24-
volt or 12-volt battery is located above the right side of
the aft landing gear cross tube.
2. Electrical Power Panel
The following switches/combination circuit breakers are
located on the switch circuit breaker panel mounted on
the instrument console within easy reach of pilot or co-
pilot: magneto key switch, master switch, alternator
switch and alternator circuit breaker, boost pump
switch, navigation position lights switch, anti-collision
light switch, panel lights, aft landing light (prior to S/N
2166), avionics master (if equipped), and trim motor
switch.
On later production aircraft, the trim motor
switch/circuit breaker is replaced with a pull-type
circuit breaker. The upper portion of the electrical panel
in the instrument console contains the switches/circuit
breakers for the lighting equipment.
7-14. Lighting Equipment
The helicopter lighting kit includes the required lights
necessary for VFR night operation plus additional lighting
equipment for utility and convenience purposes.
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