12-14. LOW FUEL LEVEL SWITCH FL3.
To conduct the low fuel level switch FL3 test, the load instrumentation and a stopwatch are required.
Test FL3 as follows:
Connect the load instrumentation in accordance with Figure 12-5.
Level the generator set.
Fill the generator set fuel tank using the fuel transfer pump.
Disconnect the auxiliary fuel lines from the external fuel tank
Start and operate the generator set at rated load, voltage, and frequency. Simultaneously start the
Note the exact time the LOW FUEL ENG FAULT indicator lights up. This should indicate that there is
enough fuel in the fuel tank to operate the set at rated load and frequency for 35 minutes.
Continue operating the set for approximately 35 minutes until the low fuel level switch FL3 shuts down
the generator set. Record the time when FL3 actuates and shuts down the set.
If FL3 does not actuate within 35 minutes after the LOW FUEL ENGINE fault indicator lights up, FL3 is
faulty or the timer on time delay (low fuel level shutdown) relay K23 is set too high. Shut down the
generator set immediately and reset the timer, or replace FL3.
12-15. SPEED SWITCH SS1/SS2/SS3.
Apparatus. Digital tachometer 3375631.
Remove left hand fan shroud associated with the radiator in accordance with the Operator and
Organizational Maintenance Manual.
Install digital tachometer 3375631 on accessory drive pulley (9, Figure 9-59).
In order to provide for manual speed control of the engine, perform the following:
Remove the two electrical wires from the fuel pump actuator (4, Figure 6-5).
Remove the rivets (42, Figure 6-11) and remove the throttle shaft cover (43).
Do not change the setting of the adjusting screw (55) located toward the front of the
fuel pump housing (66).
Loosen the hexagonal nut (54) and back out the adjusting screw (55) located toward the rear of
the fuel pump housing (66).
Lightly damp a pair of locking pliers on the splined end of the throttle shaft (45) to be used as a
The throttle shaft (45, Figure 6-11) located in the fuel pump housing (66) turns counter-
clockwise to open.
Engine speed may now be controlled manually by rotation of the throttle shaft (45).
After completion of testing, remove the locking pliers installed in step (d), above. Turn in the
adjusting screw (55) located toward the rear of the fuel pump housing (66) until the control end
(51) is locked between the adjusting screws. Tighten the hexagonal nut (54) and Install the
throttle shaft cover (43) using rivets (42).