02/25/21
Message Overview:
Message Description:
The External DC Contactor (EDCC) has failed.
Possible Causes:
- External DC Contactor (EDCC) (K81)
- Left DC Power-Center Primary-Logic (LLOG) (PCB3)
- Left DC Power Center (LDCPC) (A35)
Troubleshooting Tips:
Advisory Wire/Service Bulletin:
AW300-24-0024 - Electrical System - Troubleshooting Tips
Forum Articles/Infoservice/Newsletter: None
Quick Links:
| Removal of the Power Center (DCPC) | AMM 24-61-01-000-801 |
| Installation of the Power Center (DCPC) | AMM 24-61-01-400-801 |
| Removal of the Battery Contactor | AMM 24-61-05-000-801 |
| Installation of the Battery Contactor | AMM 24-61-05-400-801 |
| Removal of the External DC Contactor | AMM 24-61-17-000-801 |
| Installation of the External DC Contactor | AMM 24-61-17-400-801 |
| 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 |
| Standard Practices - Replace Wiring | SPM 20-12-00-02 |
| Standard Practices - Wire Repair | SPM 20-12-10-02 |
Troubleshooting Recommendations:
- Disconnect the External DC Power Contactor (K81) connector located in the Left DC Power Center (A35). Do visual inspection of the connector and associated wiring for any loose pins and/or damaged wire.
- If inspection is satisfying, continue with next step.
- If inspection is not satisfying, go to step 5.
- Verify External DC Power Contactor (K81) coils by measuring the resistances at the contactor connector (J-side) as per the following table:
Coils Expected Values Results (Pick-up) Pin 1 and Pin 2 between 4.5Ω and 6.5Ω (Hold) Pin 2 and Pin 3 between 260Ω and 280Ω - If the verification is satisfying, continue with next step.
- If the verification is not satisfying, replace the defective External DC Power Contactor.
NOTE: It is important to not skip this verification before proceeding with the swap at step 3. A short of one of the 2 coils will result with a blowing of a fuse on the Left DC Power-Center Primary-Logic (PCB3).
- Swap the External DC Power Contactor (K81) with the Left Battery Contactor (K73). Is the fault message still present?
- If YES, continue with next step.
- If NO, replace the defective External DC Power Contactor (K81).
- Swap 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 Left DC Power-Center Primary-Logic (PCB3).
- Replace Left DC Power Center (A35).
- Do close out.
