Kohler 10EOR, Service

Page: 46 / 84

TP-6073 4/06 46 Section 7 Generator Troubleshooting
7.8 Exciter Field (EORZ and
EFORZ Models)
Direct current from the battery magnetizes the exciter
field.
When the exciter armature rotates within the
magnetized exciter field windings, an electrical current
develops within the exciter armature. Test the exciter
field according to the following procedure.
Exciter Field Test Procedure:
1. Place the start/stop switch in the STOP position.
2. Disconnect the generator set engine starting
battery, negative (--) lead first.
3. Disconnect the P6 and P7 connectors (F1/F2
leads).
4. Check the exciter field resistance by connecting an
ohmmeter across the exciter field F1 and F2 leads.
See Section 1.3, Specifications, for the resistance
reading for a cold exciter field.
A low reading
indicates an internal short and a high reading
indicates an open winding. Repair or replace the
exciter field if the ohmmeter readings indicate a
inoperative exciter field (Refer to Section 9 for
removal). If the resistance test is inconclusive,
perform a megohmmeter test on the exciter field as
described in the next step.
5. Check the exciter field for a short to ground
condition. Use a megohmmeter to apply 500 volts
DC to the F1 or F2 lead and the exciter field frame.
Follow
the megohmmeter manufacturer’s
instructions for using the megohmmeter. A reading
of approximately 1.5 mOhms and higher indicates
the field winding is functional. A reading of less
than
approximately 1.5 mOhms indicates
deterioration of the winding insulation and possible
current flow to ground; if so, replace the exciter
field.
1
3
4
F1 F2
P6
TP-593658
2
1. Voltage regulator
2. Ohmmeter
3. Exciter field
4. Exciter armature
Figure 7-13 Exciter Field Resistance Test
1
3
F1 F2
P6
4
5
TP-593659
2
1. Voltage regulator
2. Ohmmeter
3. Frame connection 4. Exciter armature
5. Exciter field
Figure 7-14 Megohmmeter Connections on the
Exciter Field