13

Possible Causes

• •Binding in the governor linkage
• •Blocked heat exchanger
• •Control plugs not fully seated
• •Excessive connected loads
• •Faulty field windings
• •Faulty governor actuator operation
• •Fuel supply issues
• •Genset is loaded nearly to full power and a large motor load (such as an air conditioner) cycles on
• •Grounded or shorted main windings
• •Improper field resistance (open to ground)
• •Improper loads
• •Improper quad winding resistance
• •Incorrect engine speed
• •Incorrect loads
• •Incorrect output voltage
• •Large motor load draws up to three or more times its rated power consumption at startup
• •Loose sense lead connections
• •Opens and/or shorts in stator and rotor
• •Opens or shorts in generator field, stator, or quadrature windings
• •Overload Condition
• •Poor brush condition and contact
• •Power factor of 0.5 or less
• •Quad leads not fully seated in connector to control
• •Raw water impeller malfunction
• •Sense leads not fully seated in connector to control
• •Winding resistance not as specified

Suggested Actions

1. 1Check brush condition and contact
2. 2Check circuit breaker
3. 3Check control
4. 4Check engine speed
5. 5Check field windings
6. 6Check for binding in the governor linkage
7. 7Check for blocked heat exchanger
8. 8Check for grounded or shorted main windings
9. 9Check for proper field resistance reading, open to ground
10. 10Check fuel supply
11. 11Check governor actuator operation
12. 12Check loads
13. 13Check output voltage
14. 14Check power factor and disconnect loads that cause a power factor of 0.5 or less
15. 15Check raw water impeller
16. 16Check sense lead connections
17. 17Check stator and rotor for opens and/or shorts
18. 18Check that control plugs are fully seated
19. 19Limit the total load to not exceed 80% of the genset kW rating when powering large motor loads
20. 20Perform checks in step 01
21. 21Replace the generator rotor or stator assembly if winding resistance is not as specified
22. 22Replace the genset control PCB
23. 23Service the brushes and slip rings as necessary
24. 24Shut off some loads at times when large motor loads are active
25. 25Test the generator field, stator, and quadrature windings for opens or shorts
26. 26Turn the genset line circuit breaker OFF. If the genset runs without shutting down, run the genset with fewer connected loads
27. 27Verify control plugs are fully seated
28. 28Verify sense leads are fully seated in connector to control

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