01/20/25
Message Overview:
Message Description:
The Left DC Power-Center Primary-Logic has failed.
Possible Causes:
- Left DC Power-Center Primary-Logic (LLOG) (PCB3)
- Left DC Power-Center Protection (LPROT) (PCB1)
- External DC Contactor (EDCC) (K81)
- Left Auxiliary Bus Contactor (LAUXC) (K75)
- Left Battery Contactor (LBATC) (K73)
- Left Bus Tie Contactor (LBTC) (K79)
- Left Essential Bus Contactor (LESSC) (K77)
- Right DC Power-Center Right Bus Tie Contactor (A36K80)
- Ground Service Contactor (GSC) (K83)
- Left DC Power Center (LDCPC) (A35)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin:
- AW300-24-0013 - Loss of Normal Electrical Power
- AW300-24-0038 - Nuisance "ELECTRICAL FAULT" CAS Message Upon Engine or APU Shut Down
- AW300-24-0115 - Introduction of Improved Generator P/N A3579-102
- AW300-24-0132 - Power Module (PMOD) P/N R3608-011 - Generator Failures at High Engine Speed
- AW300-24-0137 - Y06 Electrical System Upgrade
- AW300-24-0162 - Service Bulletin 100-24-20 - DC Power Center (DCPC) System - Inspection and Replacement of Internal Fuses in the L/H and R/H DC Power Center (DCPC)
Full Throttle Blog/Forum Articles/Infoservice/Newsletter: None
Flight Operation Notifications Manual (FONM): None
| If the Aircraft is energized by the External power while both batteries are disconnected, this message will appears. Return the Aircraft to the normal configuration prior to continue with this procedure. |
Quick Links:
| Standard Aircraft Configuration for Maintenance | AMM 12-00-00-867-803 |
| Electrical/Electronic Safety Precautions | AMM 24-00-00-910-801 |
| Electrostatic-Discharge Safety Precautions | AMM 24-00-00-910-802 |
| Connect Electrical Power to the Aircraft | AMM 24-00-00-861-801 |
| Remove the Electrical Power from the Aircraft | AMM 24-00-00-861-802 |
| Removal of DC Power Center (DCPC) | AMM 24-61-01-000-801 |
| Installation of DC Power Center (DCPC) | AMM 24-61-01-400-801 |
| Removal of the Ground Service Contactor (GSC) | AMM 24-61-19-000-801 |
| Installation of the Ground Service Contactor (GSC) | AMM 24-61-19-400-801 |
| Removal of the DC Power-Center Primary-Logic | AMM 24-61-73-000-801 |
| Installation of the DC Power-Center Primary-Logic | AMM 24-61-73-400-801 |
| Removal of the DC Power-Center Protection | AMM 24-61-77-000-801 |
| Installation of the DC Power-Center Protection | AMM 24-61-77-400-801 |
| Removal of the DC Power-Center Relays | AMM 24-61-81-000-801 |
| Installation of the DC Power-Center Relays | AMM 24-61-81-400-801 |
| Wiring - Maintenance Practices - ALL | SPM 20-12-00-02 |
| Wire Repair - Maintenance Practices - ALL | SPM 20-12-10-02 |
| Electrical Connectors - Maintenance Practice - ALL | SPM 20-20-00-02 |
Troubleshooting Recommendations:
Troubleshooting Recommendations:
- Check on the EICAS if one of the following messages is posted.
- If one or many CAS messages are present, continue with the associated troubleshooting procedures.
- If none are present, continue with next step.
- Check in the MDC if one of the following faults is logged in the current faults page or in the fault history page.
- If one or many faults are present, continue with the associated troubleshooting procedures.
- If none are present, continue with next step.
- Interchange the Left DC Power-Center Primary-Logic (PCB3) with the Right DC Power-Center Primary-Logic (PCB4). Is the fault message still present?
- If YES, continue with next step.
- If NO, replace the defective DC Power-Center Primary-Logic.
- Interchange the Left DC Power-Center Protection (PCB1) with the Right DC Power-Center Protection (PCB2). Is the fault message still present?
- If YES, continue with next step.
- If NO, replace the defective DC Power-Center Primary-Logic.
- Swap the Ground Service Contactor (K83) located in the Left DC Power Center (A35) with one of the following Left DCPC relays: K44, K161 or K163. Is the fault message still present?
- If YES, continue with next step.
- If NO, replace the defective Ground Service Contactor.
- Replace Left DC Power Center (A35).
- Do close out.