Table of Contents
Advertisement
AIRCRAFT MAINTENANCE MANUAL
MISCELLANEOUS
INSTRUMENTS
Ref. Figures 8-3 & 8-5
FUEL QUANTITY INDICATOR
A fuel quantity indicator registers the
amount of fuel in either the left or right
tank, up to a maximum of 59 U.S.
gallons.
Fuel from 59 to 66.5 U.S.
gallons is un-gaugeable. The indicator
is basically a mili-voltmeter that receives
input signals from the fuel quantity
sensor (liquid level sensors). The liquid
level sensors are float operated variable
resistance transducers, one installed in
each tank. The face of the fuel quantity
indicator is marked in increments from
empty to 59 gallons.
position of the transducer float produces
a minimum resistance through the
transducer, permitting maximum current
flow through the fuel quantity indicator
and maximum pointer deflection. As the
fuel level of the tank is lowered, the float
repositions
a
contactor
resistance coil inside the transducer,
increasing resistance and thus reducing
current flow through the fuel quantity
indicator. Fuel quantity indicator needle
deflection is proportional to current flow
through.
The fuel quantity indicating
system is calibrated prior to leaving the
factory, but should be re-calibrated if
there are any indications of inaccurate
fuel level readings. Calibration can be
done as outlined in Section 5.
VOLTMETER
A voltmeter displays electrical system
voltage when the master switch is on
8-10
Page
THRUSH AIRCRAFT, INC – MODEL S2R-G10
The full tank
along
a
and allows the pilot to monitor bus bar
voltage.
Normal voltmeter readings must
be within the green arc (24.0 to 30.5 volts).
Insufficient voltage or overcharging is
indicated by a lower red arc (minimum) 16.0
to 22.5 volts, and an upper red arc
(maximum) 30.5 to 36.0 volts respectively.
Continuous operation over 30.5 volts is
detrimental to the life of the battery and
could cause loss of electrical power.
yellow arc from 22.5 to 24.0 volts indicates
a caution range.
AMMETER
The ammeter displays current flow, in
amperes, from the aircraft alternator to the
battery, or from the battery to the electrical
system.
With the engine operating, the
ammeter should indicate the on charge (+)
side unless there is an aircraft alternator
malfunction. A discharge (-) indication will
show if the alternator is not working or if the
electrical load demand exceeds the aircraft
alternator output. Continuous operation on
the discharge side will be detrimental to
battery life and may cause loss of electrical
power.
HOPPER QUANTITY (Optional Equip.)
The hopper quantity consists of three parts
-- the level sensing element in hopper, FA-
A control box normally located on left side
of cockpit, and quantity gauge located in
instrument panel. The gauge is adjustable
between 0 gallons to 360 gallons and
incorporates two lights, one amber light for
low quantity, and one red right for hopper
empty. The system can be calibrated per
the following instructions.
A
Effective: 03/26/2010
Advertisement
Chapters
Table of Contents
Troubleshooting
