Low insulation resistance may be caused by
dirt or excessive moisture. Insulation failure
may be caused by wrong voltages, induced
voltages caused by opening field circuits
Windings may be dried out by heat from a
warm air oven, heat lamps, or strip heaters.
The temperature should not exceed 167°F
WHEN OVEN DRYING, USE A FORCED AIR
CIRCULATION OVEN, NOT A RADIANT
TYPE. RADIANT TYPE OVEN WOULD
OVERHEAT SOME GENERATOR PARTS
BEFORE REMOTE PARTS REACHED A
Replacement. For removal and replacement of
the exciter stator, refer to paragraph 11-6.
Replace or rebuilt all defective parts.
To remove coils from core, heat in a
moderate oven temperature 302°F (150°C) to
facilitate removal. Single coils should not
be replaced as adjacent parts of the winding
may be damaged during coil removal.
Apply varnish to any damaged areas of
Replace damaged exciter stator.
Rebuild exciter stator as follows:
Single wires may be spliced by brazing.
The splice is to be insulated by sliding
sleeving over the wire prior to brazing
relocating the sleeving over the splice after completion.
The sleeving is to extend a minimum of
1/2 inch (13 mm) beyond the bare
uninsulated portion of wire. The sleeving
material is to be the same as that used
for crossovers on the connection end.
Splices shall be made in the end turn of
the coil only and shall not be made in the
straight leg. Where more than one splice
is required, the second splice must not
occur on the same coil end and must not
occur in adjacent coils. Where more than
one splice is necessary in the same coil
or an adjacent coil, the splice may be
made in the connection end of the coil.
extensions. Cleaning is to start as near
sleeving as possible. Clean a 1/2 inch (13
mm) section of wire end projecting from a
projecting from a sleeving section shall be 3
inches (76 mm) minimum to 5 inches (127
mm) maximum. Wire diameter is to be
reduced a maximum of 5 percent. Cleaned
area shall have enamel removed over 80
percent of the surface.
Slot tubes should be inserted with overhang
equally divided on ends. Minimum slot
tube overhang (distance from core to end of
slot tube) shall be 1/4 inch (6 mm).
Position of the