Main Field (Rotor) - Kohler Power Systems 8RESV Service Manual

8. If the resistance test proves inconclusive, use a
megohmmeter to test the stator as described in the
next step.
Note: Because ohmmeter
resistance
readings. Take readings of the rotor and
stator at room temperature.
Note: Make sure that all stator leads are
disconnected
megohmmeter test.
9. Use a megohmmeter to determine whether the
stator is shorted to ground.
a. Apply 500 volts DC to any stator lead and the
stator frame. Perform the megohmmeter test
following the instructions of the megohmmeter
manufacturer.
b. Repeat the test on the other stator leads until
each coil is tested.
Note: A reading of approximately 500 kOhms
(1/2 megohm) and higher indicates a
good stator.
c. Repair or replace the stator if any reading is
less than approximately 500 kOhms. A reading
of less than 500 kOhms indicates deterioration
of the winding insulation and possible current
flow to ground.

5.5 Main Field (Rotor)

The two-pole rotor creates the magnetic field needed to
produce alternating current in the stator windings.
Before testing, inspect the rotor for visible damage to
pole shoes, insulation, exposed coil windings, and slip
ring surfaces. Rotate the bearing to check for wear, heat
discoloration, or noise.
80 Section 5 Component Testing and Adjustment
accuracy varies,
readings are approximate
before running
Hazardous voltage.
Can cause severe injury or death.
Operate the generator set only when
all guards and electrical enclosures
the
are in place.
High voltage test. Hazardous voltage can cause severe
injury or death. Follow the instructions of the test equipment
manufacturer when performing high-voltage tests on the rotor
or stator. An improper test procedure can damage equipment
or lead to generator set failure.
Grounding electrical equipment. Hazardous voltage can
cause severe injury or death. Electrocution is possible
whenever electricity is present. Ensure you comply with all
applicable codes and standards.
generator set, transfer switch, and related equipment and
electrical circuits. Turn off the main circuit breakers of all
power sources before servicing the equipment. Never contact
electrical leads or appliances when standing in water or on wet
ground because these conditions increase the risk of
electrocution.
Accidental starting.
Can cause severe injury or death.
Disconnect the battery cables before
working
Remove the negative (--) lead first
when disconnecting the battery.
Reconnect the negative (--) lead last
when reconnecting the battery.
Disabling the generator set.
cause severe injury or death.
generator set or equipment connected to the set, disable the
generator set as follows: (1) Press the generator set off/reset
button to shut down the generator set. (2) Disconnect the
power to the battery charger, if equipped. (3) Remove the
battery cables, negative (--) lead first. Reconnect the negative
(--) lead last when reconnecting the battery. Follow these
precautions to prevent the starting of the generator set by the
remote start/stop switch.
WARNING
Moving parts.
Electrically ground the
WARNING
on the generator set.
Accidental starting can
Before working on the
TP-6881 7/15