TM 55-1930-209-14&P-9-1
(1)
Electronic overspeed shutoff switch uses a magnetic pickup mounted in the flywheel housing to sense
engine speed. When engine overspeeds, magnetic pickup doses circuit to fuel shutoff solenoid and stops
the engine. When engine stops, switch the ECS or ENGINE START/STOP switch to STOP Troubleshoot
and repair as necessary. Reset overspeed shutoff switch, either on engine overspeed panel or on
switchboard SSG panel. Restart engine by following procedures in paragraphs 2-11 and 2-13.
(2)
The overspeed sensing device has a second sensing circuit that prevents the starter pinion from remaining
engaged in the flywheel at excessive rpm. After starter has cranked the engine, pinion gear may remain
engaged in flywheel as engine speed increases. At 600 rpm, the magnetic sensing device opens a circuit
to the starter and disengages pinion. This circuit remains open until flywheel stops. The open circuit
prevents starter from energizing while flywheel is turning. This safety device does not require resetting.
2-13.
Operating procedures from switchboard. Starting procedures for the engines are in paragraph 4-12 for SSG’s
and 5-12 for SAG. Operating procedures using shore power are in paragraph 2-15.
a.
Turn ENGINE CONTROL SWITCH (Figure 2-11) to START. Engine will crank and run.
b.
Allow engine to idle for 2 minutes.
c.
Monitor the following:
(1)
ENGINE FAILURE LIGHTS do not light (Figure 2-11).
(2)
Battery charger ammeter DC AMPS and DC VOLTS meters (Figure 2-15) indicate ammeter is charging
batteries.
(3)
440 VOLT GROUND DETECTION lights do not light (Figure 2-12 or 2-13).
d.
Turn VOLTAGE REGULATOR switch to RUN (Figure 2-11).
e.
Wait 1 minute for engine to stabilize.
f.
Monitor items listed in step c above.
g.
Using AUTOMATIC VOLTAGE CONTROL RHEOSTAT, set generator voltage to 450 V.
h.
Set generator frequency to 60 Hz.
(1)
On SSG 1 or SSG 2, use GOVERNOR SPEED CONTROL toggle switch (Figure 2-11). Move it left to
increase frequency and right to decrease frequency.
(2)
On SAG, GOVERNOR SPEED CONTROL toggle switch is not connected (Figure 2-11). Set SAG
generator frequency by adjusting throttle on right side of switchboard. Turn throttle knob clockwise to
increase frequency and counterclockwise to decrease frequency.
i.
Check ENGINE FAILURE LIGHTS (Figure 2-11) by pressing-to-test. Lights should light when pushed in. If not,
make note of bulbs to be changed when that generator is off-line.
CAUTION
If this Is first generator to be started and placed online, proceed with steps thru m. N
another generator Is currently providing power, follow procedures In paragraph .2-14
j.
When the values in steps g and h are stable, dose appropriate switchboard circuit breaker (Figure 2-14) to
provide generator output to switchboard bus:
P3 for SAG
P2 for SSG 2
P1 for SSG 1
2-25
