Onan

27

UnclassifiedElectrical

What This Code Means

Loss of AC Sense; Excessive Smoke Under Load; Loss of voltage sense; Loss of quad sense; Engine stopped

Possible Causes

  • •AC sense circuitry lack of continuity
  • •AC sense transformer resistance out of specification
  • •Broken voltage sense leads
  • •Control fault
  • •External shorts
  • •Faulty genset control PCB
  • •Fuel supply issue
  • •Loose voltage sense leads
  • •Mechanical engine damage
  • •Overload Condition
  • •Rotor resistance open, short, or ground
  • •Stator resistance open, short, or ground

Suggested Actions

  1. 1Check AC output
  2. 2Check AC sense circuitry (Voltage Sense Input signal to genset control PCB) for continuity
  3. 3Check battery connection to battery & set
  4. 4Check battery voltage to set
  5. 5Check field resistance
  6. 6Check fuel supply
  7. 7Check mechanical engine damage
  8. 8Check resistance of AC sense transformer (H1 to H2 - 309 ohms ± 10%, X1 to X2 - 391 ohms ± 10%)
  9. 9Check rotor resistance (opens/shorts/grounds)
  10. 10Check stator resistance
  11. 11Check stator resistance (opens/shorts/grounds)
  12. 12Check voltage sense leads
  13. 13Replace the genset control PCB
  14. 14Troubleshoot Control
  15. 15Troubleshoot external shorts

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