ARMY *TM 9-6115-464-34 AIR FORCE TO-35C2-3 ... - Igor Chudov

ARMY TM 9-6115-464-34AIR FORCE 35C2-3-445-2NAVY NAVFAC P-8-624-34(1)(2)(3)(4)(5)(6)c. Removal.If the FL-NL or NL - FL transient exceeds 1-1/2 percent of rated speed and/or does notreestablish stable engine operating conditions within one second, realign the control unit inaccordance with paragraph 3-64j. Also follow this procedure if the engine speed hunts. If the setcannot be stabilized, check sockets A and B of plug P-21 (figure 3-97) for 24 Vdc (A is positive).If the engine speed increases to above nominal operating speed, check sockets A and B of P-17(figure 3–97) for 120 Vac. If it is missing, troubleshoot the generator set wiring. Refer to schematicand troubleshooting diagram plates located on inside of left and right engine compartment doors(figure 3-97). If it is present, check the resistance of the frequency adjusting circuit consisting of R4(250 ohms) rheostat R1 frequency adjust (500 ohms) and R6 (250 ohms) fixed resistor. Measure thetotal circuit resistance across N and T of harness plug PI 7 (figure 3-97). The circuit resistanceshould be 1000 ohms (5 percent tolerance). After testing for correct total resistance, test theoperation of the frequency adjust rheostat by connecting an ohmmeter across pins M and T andrevolving the frequency adjust rheostat through its entire travel. The resistance should vary from 750ohms to 250 ohms. Repeat this procedure using the ohmmeter across pins M and N of the harnessplug. If the problem persists, check sockets A and B of plug P-21 (figure 3-97) for 24 Vdc (A ispositive).If the engine speed remains below the nominal operating speed, adjust RI. If there is noimprovement, check the resistance of the frequency adjust circuit. Disconnect P–17 and check theresistance of the frequency adjust circuit consisting of R4 (250 ohms) fixed resistor, RI frequencyadjust rheostat (500 ohms) and R5 (250 ohms, 5 percent) fixed resistor. Measure the total circuitresistance across N and T of harness plug P-17. The circuit resistance should be 1000 ohms (5percent tolerance). After testing for correct total resistance, test the operation of the frequency adjustpotentiometer by connecting an ohmmeter across pins M and T and revolving the travel. Theresistance should vary from 750 ohms to 250 ohms. Repeat this procedure using the ohmmeteracross pins M and N of the harness plug. Disconnect actuator electrical connector before making thismeasurement. Push actuator piston all the way down and adjust engine speed with manual throttle.If this value resistance is measured, check sockets A and Bat plug P–21 for 24 Vdc (A is positive).If the set is operating at a constant load and voltage and during an eight–hour period the change inambient temperature does not exceed 60°F, the set frequency should not drift beyond 1/2 of onepercent of rated frequency. The above requirement assumes that the set temperatures werestabilized at the initial and final ambient temperatures.NOTEIf the drift in paragraph (4) is excessive, realign the control unit following the procedureoutlined in paragraph 3-64j.At constant ambient temperature, constant load, constant voltage and constant barometric pressure,the set frequency should remain within a bandwidth of 1 percent of rated frequency for a period of 4hours. If this bandwidth has been exceeded, realign the control unit in accordance with paragraph3-64j.If the preceding solutions to the specific problem do not resolve the problems, replace and repair thecontrol unit, actuator (paragraph 3-43) or load measuring unit (paragraph 3–63) as required.(1) Tag and disconnect electrical connectors to governor control unit.(2) Remove nuts (1, figure 3-68), Iockwashers (2), nuts (3), Iockwashers (4) and bracket (5), threadedrod (6) and lift governor control unit from mounting bracket.3-158