INU-LSU comm loss

What does AF80 mean?

DDCS (fiber optic) communication between converters (e.g., inverter unit and supply unit) has been lost. The inverter unit will continue operating based on the last received status, but synchronized operation and full diagnostics are compromised. Loss of communication can lead to system instability or incorrect power flow.

• Broken or kinked fiber optic cable (DDCS link) between the inverter unit (INU) and the supply unit (LSU).
• Contaminated or damaged fiber optic connectors at either the INU or LSU communication module (e.g., RDCU-XX or SDCS-PIN-XX).
• Incorrectly seated fiber optic transceiver module in the INU or LSU, leading to no light transmission or reception.
• Faulty fiber optic transceiver module (e.g., SDCS-PIN-501) on either the inverter unit or the supply unit.
• Loss of control power (e.g., 24VDC) to one of the units (INU or LSU), preventing its DDCS module from functioning.

Click steps to track your progress.

1. 1

   Visually inspect the fiber optic cable (DDCS link) between the INU and LSU for any physical damage, sharp bends, or cuts.

2. 2

   Power off both the INU and LSU. Carefully clean the ends of the fiber optic cables and the transceiver ports using a suitable fiber optic cleaning kit.

3. 3

   Power off both units. Re-seat the fiber optic transceiver module (e.g., SDCS-PIN-501) in both the INU and LSU control boards.

4. 4

   With power applied, check the status LEDs on the fiber optic communication modules (e.g., green for link, flashing yellow for activity) on both INU and LSU.

5. 5

   Temporarily swap the fiber optic cable with a known good one (of correct length) between the INU and LSU to rule out cable failure.

6. 6

   Check control voltage supply (e.g., 24VDC) to both INU and LSU control boards at their respective terminals to ensure they are powered correctly.