3
Operating Instructions
Alternator field is not energized
Low output voltage with no load
High output voltage with no load
Low output voltage under load
Erratic output voltage
Noisy operation
1. Engine speed is too slow
2. Open, shorted, or incorrect wiring
3. Faulty capacitor
4. Open or shorted field windings
5. Open diodes
1. Engine speed is too slow
2. Open diodes
3. Faulty capacitor
4. Open or shorted field windings
1. Faulty capacitor
2. Engine speed is too fast
1. Open diode
2. Engine speed too slow at full load
3. Excessive load applied
1. Unbalanced engine
2. Dirty, corroded, or loose wiring
connection
3. Unstable load applied
1. Loose generator or engine bolt
2. Short circuit in generator field or load
3. Faulty bearing
1. Adjust engine speed
✽
2. Referring to the wiring diagram, clean
and reconnect all wiring
✽
3. Replace capacitor
✽
4. Test winding resistance, replace field
winding if necessary
✽
5. Test diodes, replace if necessary
✽
1. Adjust engine speed
✽
2. Test diodes, replace if necessary
✽
3. Replace capacitor
✽
4. Test winding resistance, replace field
winding if necessary
✽
1. Replace capacitor
✽
2. Adjust engine speed
✽
1. Test diodes, replace if necessary
✽
2. Adjust engine speed
✽
3. Reduce the applied load
1. Refer to engine manual
2. Referring to the wiring diagram, clean
and reconnect all wiring
✽
3. Remove all loads, then apply each one
individually to determine which one is
causing erratic function
1. Tighten all mountings
2. Test winding resistance, replace field
winding if necessary
✽
Test load devices for shorts. Replace
defective load device.
3. Replace bearing
✽
These diagnostic and repair procedures should be performed by an authorized service center.
Troubleshooting Chart
Symptom
Possible Cause(s)
Corrective Action
Fig. 4 - Wiring Diagram for GN2560V and GN2563V
GN2560V, GN2563V, GN3560V and GN3565V
Rotor
Stator
Ground
Main Winding
120V
Excitation
Winding
Capacitor
Plug
Circuit Breaker
120V Duplex Receptacle
NEMA 5-15R
1
2
3
4
Main Winding
120V
G
W
BK
BK
W
