ARMY TM 9-6115-642-24
AIR FORCE TO 35C2-3-455-12
MARINE CORPS TM 09247A/09248A-24/2
a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
k.
4-10.6
Shut down generator set. Allow generator to cool to ambient temperature.
Open left side engine access door and disconnect negative battery cable.
Open storage box and output terminal board access doors.
Remove end bell cover from generator, paragraph 4-11.1, step e (MEP-803A) or paragraph 4-12.2, step h
(MEP-813A).
Tag and disconnect lead wires from diodes CR1, CR2, CR3, CR4, CR5, and CR6 on rotating rectifier.
Connect resistance bridge between leads CR1 and CR2, CR2 and CR3, CR1 and CR3, CR4 and CR5, CR4
and CR6, and CR5 and CR6. Resistance between leads should be as shown in TABLE 4-1.
Readings other than shown in TABLE 4-1 indicate open or shorted windings and exciter rotor must be replaced.
Connect leads of multimeter between each CR lead and exciter rotor lamination. Multimeter reading less than
infinity indicates defective ground insulation and exciter rotor must be replaced.
Connect exciter rotor lead wires to diodes CR1, CR2, CR3, CR4, CR5, and CR6. Tighten nuts to 24 in-lbs (2.7
Nm) and remove tags.
Install end bell cover on generator, paragraph 4-11.4, step n (MEP-803A) or paragraph 4-12.5, step g
(MEP-813A).
Connect negative battery cable and close access doors.
Testing Generator Rotor. Set multimeter for ohms and test the generator rotor, for open or shorted windings and
grounds as follows:
a.
b.
c.
d.
e.
f.
9.
Shut down generator set. Allow generator to cool to ambient temperature.
Open left side engine access door and disconnect negative battery cable.
Open storage box and output terminal board access doors.
Remove end bell cover from generator, paragraph 4-11.1, step e (MEP-803A) or paragraph 4-12.2, step h
(MEP-813A).
Disconnect rotor leads F1 + and F2- from rotating rectifier assemblies.
Connect multimeter between F1+and F2- leads (FIGURE 4-20). Resistance reading should be as shown in
TABLE 4-1.
If resistance is low, there are shorted windings. If resistance is high, rotor winding is open. In either case, rotor
must be replaced.
FIGURE 4-20. Testing Rotor for an Open or Shorted Windings.
4-22
