TM 55-2210-224-34
3-37.
MAIN GENERATOR (cont)
TEST (cont)
31. Perform bar-to-bar resistance test.
a.
Place lead (1) of multimeter (2) on the shaft or core of armature (44).
b.
Place lead (3) of multimeter (2) on one of the commutator bars. Note and record indications on multimeter.
Place lead on each successive bar around the commutator and record each indication.
c.
If resistance indications are 10 percent or more above the average recorded indications on 20 or more
connections, TIG weld all coil leads to commutator neck connections. Resistance indications of 1/2 percent
below the average, or a full-scale meter deflection of the multimeter, indicates a shorted coil to the armature.
WARNING
Procedures specify the heating of parts to aid in disassembly and assembly. Heated
parts may cause injury to personnel if hand protection is not worn when handling.
Wear protective gloves for maximum protection.
d.
Below-average readings could indicate the presence of water in the coils. If below-average readings are
obtained, bake armature in a convection oven for 4 hours at 230° (110°C).
e.
Cool at room temperature and repeat steps a and b above.
f.
If readings are still low, replace armature.
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