Thomson Power Systems

TRANSFER FAIL

UnclassifiedSensors

What This Code Means

TSC 900 Transfer Fail alarm activated; Will not re-transfer to utility source upon restoration; Will not transfer to generator source upon failure of utility source; Transfer to generator source without a power failure in the utility source; Forced transfer to the generator supply is activated; Generator start signal is initiated; Load transfers to the generator supply; Re-transfer back to the utility supply does not occur; ‘On Utility’ LED flashes; ‘Alarm’ LED is activated; Alarm output signal on customer terminals #5 & #6 is activated; Forced transfer to the utility supply is activated; Load automatically transfers to the utility supply; Re-transfer back to the generator supply does not occur; ‘On Gen’ LED flashes; Forced transfer to the generator supply; Re-transfer back to the utility supply will not occur; 'On Utility' LED flashes; 'Alarm' LED activated; Forced transfer to the utility supply; Re-transfer back to the generator supply will not occur; 'On Gen' LED flashes; Fail to ex

Possible Causes

  • •ATS Power Chassis & Voltage Sensing Isolation Plugs (PL12 or PL15) are unplugged
  • •Defective Power contactor unit close coil
  • •Defective Power contactor unit trip coil
  • •Utility Return Time delay period in TSC 900 has not yet expired
  • •A Load Test mode has been activated locally or remotely
  • •An Exercise Test mode has been activated by the TSC 900 scheduler
  • •Utility supply is not operating at correct voltage or frequency levels
  • •TSC 900 has incorrect utility voltage or frequency settings for the ATS
  • •Utility Phase Rotation is not matched with Generator supply (first time transfer)
  • •TSC 900 connection plugs are unplugged (J1,2,3,4)
  • •TSC 900 has 'Transfer Fail' alarm activated
  • •Faulty Power contactor unit
  • •A loose control wire connection
  • •Defective TSC 900 controller
  • •Faulty Power Contactor unit auxiliary contact
  • •Transfer Mode selector is not in "Auto" position
  • •A Transfer Inhibit signal has been activated
  • •Warm-up time delay function has not timed out yet
  • •Generator set output circuit breaker which feeds ATS is open
  • •TSC 900 has incorrect generator voltage or frequency settings for the ATS

Suggested Actions

  1. 1Verify both PL12 & PL15 connectors are fully inserted
  2. 2Determine cause of alarm and rectify before TSC 900 is reset on GHC
  3. 3Refer to Power Contactor unit Troubleshooting Section
  4. 4Verify TSC 900 time delay setting
  5. 5Check TSC 900 GHC Home Page status indicators
  6. 6Check TSC 900 GHC Scheduler page
  7. 7Verify correct nominal levels the utility source should be operating at and compare to TSC 900 settings for under/over voltage, voltage phase balance and under/over frequency
  8. 8Re-Program TSC 900 with correct settings as required for voltage or frequency
  9. 9Check Generator & Utility Voltage Phase rotation matches on TSC 900 GHC Utility & Generator Voltage Pages. If power cabling has non-matching phase rotation, reverse power conductors on one phase on one of the supplies
  10. 10Verify all TSC 900 connectors are fully inserted
  11. 11Check all wiring connections in the ATS
  12. 12Verify TSC 900 has 120VAC control power applied to the utility control power input (J1
  13. 13Verify Generator & Utility auxiliary contacts are operating correctly. If defective, return to Thomson Power Systems using RMA process
  14. 14Turn Transfer Mode selector to "Auto" position
  15. 15Check TSC 900 indicators if a utility transfer inhibit signal has been activated and reset
  16. 16Verify TSC 900 timer setting
  17. 17Close generator set output circuit breaker
  18. 18Verify correct nominal levels the generator should be operating at and compare to TSC 900 Settings for under/over voltage, voltage phase balance, and under/over frequency
  19. 19Turn Transfer Mode selector to “Auto” position
  20. 20Verify TSC 900 has 120VAC control power applied to the generator control power input (J1 - 12, 13) and Diagnostic green LED is flashing

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