analyzer's electrical system measurement components
Monitoring.--Monitoring is accomplished by a
group of analyzer master controls for the engine and a
and for introducing auxiliary power into the analyzer's
bank of eight individual controls for individual engine
monitoring circuits.
components. A 28-pin electrical connector (J1)
Speed Measurement.--Speed measurement is
provides for the interconnection of the analyzer
accomplished with a tachometer (M1). The tachometer
monitoring controls and circuits to the engine being
contains two dials with ranges of 0 to 2,500 rpm and
tested. The cable that provides this interconnection is a
2,500 to 5,000 rpm. The conversion chart attached to
part of the special tools for each specific engine.
the cover door provides conversion factors for various
Reference must be made to the applicable engine's
engine gear ratios for determining actual engine speed.
technical manual for this cable.
Two jacks (K17 and K18) provide connection from the
The analyzer master controls include an engine
tach generator into the tachometer circuit; ground is
start switch (S3) and stop switch (S1) that provide for
provided through the monitoring circuit.
starting and stopping the engine at the analyzer
Exhaust Temperature Measurement.--Exhaust
(instead of the service installation or other control
temperature measurement is indicated on a
panel). A starter switch (S4) is used for motoring the
temperature indicator (T2). A special two-pin
engine only. A load light (L1) provides an indication of
electrical connector (J5) provides connection from the
engine readiness for applying a load; switch S7
engine exhaust thermocouple into the temperature
controls the engine load control valve.
indicator.
The eight banks of individual monitoring circuits
monitor the following engine circuits or components:
O i l Te m p e r a t u r e M e a s u r e m e n t . -- O i l
auxiliary No. 1, auxiliary No. 2, load valve, starter,
temperature measurement is accomplished by a
ignition, fuel, relay No. 1, and relay No. 2. Switches S5
temperature indicator (T1) with a range of 0 to 150C.
through S11 are three-position switches and control
Two jacks (K22 and K23) provide connection into the
seven of the circuits. With the engine powered, the
indicator circuit; 28-volt dc power is available to the
DOWN (No. 3) position provides a shunt across the
indicator through the monitoring circuit.
jacks in that particular circuit for dynamic checks. The
Frequency Measurement.--A frequency meter
MIDDLE (No. 2) position opens the circuit across the
(M2) with a range of 380 to 420 hertz is used for
jacks for measurement purposes. The UP (No. 1)
f r e q u e n cy m e a s u r e m e n t . T h i s m e a s u r e m e n t i s
position applies direct current into the circuit for static
obtained and used when checking engines that drive ac
test of the component or circuit.
generators. A two-pin electrical connector (J4)
Switch S2 is a two-position switch (spring-loaded
provides connection into the meter circuit.
OFF) that allows for monitoring the start circuit. In the
Resistance Measurement.--Resistance
UP position, the starter circuit is opened for
measurement is obtained by an ohmmeter (M6). The
measurement purposes. With the engine powered, the
ohmmeter reading can be changed (R 1 or R 10) by
DOWN (OFF) position of the switch shunts across the
jacks for dynamic checks.
one or the other of the resistors (R2 and R3) connected
into the meter circuit by switch S14. A 1.5-volt battery
The eight press-to-test indicator lights (L2 through
(B1) supplies the power source for the ohmmeter
L9) indicate the presence of power in a particular
circuit. A potentiometer (R1) provides the zero setting
circuit. The light will illuminate if the circuit has
of the meter, with two jacks (K32 and K33) provided
power. Jacks in pairs provide access into each of the
for the meter connections.
eight monitor circuits. The analyzer's monitor circuits
are protected by a 5-ampere fuse (F1).
Current Measurement.--Current draw can be
measured by a 0 to 5 ampere dc ammeter (M4). Meter
FUEL, OIL, AND PNEUMATIC SYSTEM.--
connections are provided through two jacks (K28 and
The analyzer's fuel, oil, and pneumatic system
K29).
provides components for measurement of engine oil
pressure, fuel pressure, and control air pressure. The
Voltage Measurement.--Voltage is measured
analyzer also provides for regulation of the engine
with a dc voltmeter (M3) and an ac voltmeter (M5).
control air.
Jacks K26 and K27 for dc voltages and K30 and K31
for ac voltages are used to connect the voltmeters into
The components of the fuel, oil, and pneumatic
the different circuits being measured.
system include pressure gauges, elbow connections,
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