09/13/19
Message Overview:
Fault Message:
APU SHUT DOWN - LOSS OF DC POWER
Fault Code:
4960119APU
Associated CAS:
| Reporting LRU: | Full-Authority Digital Engine-Controller (FADEC) |
| System Description: | 49-60-00 |
| Schematic Diagram: | 49-61-00 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Wiring Diagram: | 49-12-01 [ Global Express ] [ G5000 ] [ Global XRS ] 49-61-01 [ Global Express ] [ G5000 ] [ Global XRS ] |
Fault Description:
The Full-Authority Digital Engine-Controller (FADEC) stopped the Auxiliary Power Unit (APU) or recorded incorrect power inputs because of one or more of the conditions that follow:
- A FADEC internal fault flag is set at power up (this fault flag shows that power was lost during the last FACEC operation)
- Primary power to the FADEC is less than seven volts
- Secondary power to the FADEC is less than seven volts
- There was an APU shutdown due to loss of both primary and secondary power to the FADEC for more than 200 msec
| Fault | See * below | Description |
|---|---|---|
| FADEC FAILURE | ECU internal failure (CPU, watchdog timer, O/S circuit failure, loss of O/S protection, etc.) |
|
| O/SPD | (Hardware/Software) overspeed circuits tripped (at 106%) | |
| LOSS OF SPEED | Both monopoles failed | |
| LOSS OF O/SPD | FADEC overspeed circuit/FCU fuel output solenoid failed | |
| OVERTEMP | * | EGT limit exceeded during i) start ii) on-speed operation |
| FIRE EMERG | * | Fire signal is received by the FADEC |
| REVERSE FLOW | * | T2 temp. limit (176.6 °C/350 °F) has been exceeded for 5 secs |
| HIGH OIL TEMP | * | Oil temp limit of >148.9 °C exceeded for 10 seconds |
| LOW OIL PRESS | * | Oil pressure has fallen below lower limit of 30 psig for 15 seconds with rpm >95% |
| LOSS OF EGT DETECTION | * | Both EGT thermocouples have failed ( NOTE: In Essential Mode, FADEC programs an EGT of 260 °C to maintain the APU running) |
| NO FLAME | EGT rise has not been detected within 17 seconds of fuel solenoid being commanded open by FADEC, or rpm > 18% for 5 seconds |
|
| NO ACCEL | Acceleration is < 0.05% of the prescheduled rate (normal acceleration is 2.5% per seconds) | |
| SLOW SPEED | Starter timer expired - APU rpm > 5% and less than starter cut out for 30 seconds | |
| UNDER SPEED | * | Speed has reached 100%, then drops below 80% for 5 secs |
| NO CRANK | rpm does not rise above 5% within: a) 2 secs. when oil temp is warmer than minus 23 °C, or b) 50 secs. when oil temp is minus 23 °C or lower |
|
| INLET DOOR | Inlet door position indicates closed 30 secs before starter engagement, or 600 msecs. after starter engagement |
|
| LOSS OF DC POWER | Loss of 28 VDC power for 200 milliseconds | |
| LOP SW FAIL | * | Oil pressure switch has failed open when rpm is <7%. ( NOTE: This switch is normally closed during prestart BITE) |
| FALLBACK | APU drop below 25% rpm after starter cutout | |
| APU GCU HIGH OIL TEMP | * | APU Generator oil temperature above 215 °C |
NOTE: An asterisk mark (*) in any row above means that the automatic protection shut down on that row is inhibited if the associated fault occurs in flight. The respective CAS message, or an advisory message reading APU FAULT will be displayed in the CAS window and the APU will not shut down automatically in flight. However the pilot may select to shut down the APU manually by placing the APU Control Switch to OFF.
Possible Causes:
- Auxiliary Power Unit (APU) Full-Authority Digital Engine-Controller (FADEC) (A108)
- DC Power Center (DCPC) (A63)
- Secondary Power Distribution Assembly (SPDA) 3 (A15)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
If CAS message is not active, verify stored faults on CAIMS.
Quick Links:
| Removal of the DC Power Center (DCPC) | AMM 24-61-00-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of the DC Power Center (DCPC) | AMM 24-61-00-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Removal of the Secondary-Power Distribution Assemblies | AMM 24-62-01-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of the Secondary-Power Distribution Assemblies | AMM 24-62-01-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Removal of the Engine Branched Wiring-Harness | AMM 49-12-01-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of the Engine Branched Wiring-Harness | AMM 49-12-01-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Removal of the Full-Authority Digital Engine-Controller (FADEC) |
AMM 49-61-01-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of the Full-Authority Digital Engine-Controller (FADEC) |
AMM 49-61-01-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Wire Repair - Maintenance Practices - ALL | SPM 20-12-10-02 [ Global Express ] [ G5000 ] [ Global XRS ] |
Troubleshooting Recommendations:
- Re-rack FADEC and verify condition of connector A108AP1, A108BP1 and A108CP1 as well as APU mounting tray connectors for damage or FOD.
- Put Batt Master ON.
- On DC electrical synoptic page verify both APU/Avionic battery voltages.
- On EMS CDU check SSPC APU FADEC POWER 1 c/b is not out or pulled, and also DCPC APU FADEC POWER 2 c/b CB-B5 is not out or pulled.
- If battery voltages are not good, repair defective wiring as required and do close out.
- If battery voltages are good, continue with next step.
- Perform voltage check on FADEC connector as follows:
From To Expected Result Result A15P1-k A108BP1-115 28 Volt A63P3-P A108BP1-114 28 Volt Ground A108BP1-113 28 Volt - If voltage checks are good, do close out.
- If voltage checks are not good, continue with next step.
- Verify all APU tray ground connections.
- Replace FADEC.
- Do close out.