Issue faced:
A client has faced an issue where the installed LUNA2000-10-S0 no longer have any LED indication the next day after initial turn on. Further on that, the LUNA2000 went offline on FusionSolar and can no longer charge or discharge. The connected SUN2000 has no issue in normal operation.
Possible cause:
The external electrical connection of the LUNA2000 was not connected properly.
Initial resolution steps:
Press on the LUNA2000 black start button for 5 seconds to determine if the DCDC can be powered on manually to determine if it is an issue on the DCDC.
If Step 1 does not work, it is required to check whether the voltage from SUN2000 to the BAT cable of LUNA2000 is normal, if the BAT cable voltage is normal, the next step is to connect the BAT cable back to the DCDC and turn the LUNA2000 back on.
To measure the voltage again on the other side of the DCDC to see if the voltage reading is tally.
a) Reading of 138V from SUN2000 b) Reading of 21.5V on the other side of DCDC
Results of initial resolution steps:
It was determined that the DC input terminal is not in proper contact with the DCDC as the voltage reading does not tally with each other. After proper termination, the DCDC module is back to working.
However, the issue is not solved as the LUNA2000 communication is still not established with the SUN2000. Therefore, the next course of action is to check on the COM port on LUNA2000 and if the RS485 communication cables are properly connected.
Next course of action:
After a thorough checking on the connection of the RS485 communication cables, it was determined that the connection was loose and the Enable signal of the COM port was connected to the wrong pin. Therefore, the RS485 cable have to be rewired and reconfigured.
a) Communication cables (before) b) Communication cables (after)
Therefore. this case study serves as an important notice to double check any wiring connections as well as to determine if the cables are connected to their designated pins as per according to user manuals and quick guides.
