Hi Everyone and Happy New Year!

[DWills784]

Just introducing myself. I'm Dee, a DIYer with an off-grid solar system. I have a lot to learn especially since my system is not working. I'm hoping someone can assist. In case I can do it here, I'll go ahead and state my problem here. Thanks in advance for any advice you can offer.

Question: Assistance with Repeated F12 Error (DCDC Overcurrent) on MPP Solar 8048MAX and Blown ATS Switch

I’m seeking advice on an issue with my off-grid solar system, as I’m getting conflicting opinions from technicians. Here’s a summary of my setup and the problem:

System Details:

• Local Voltage/Frequency: 230V, 50 Hz
• Inverter: MPP Solar 8048MAX (8kW/48V off-grid inverter)
• Batteries: 3 x EG4-LifePower4 Lithium Battery (48V, 100AH, UL 1973)
• PV Panels: 12 x 460W Greensun solar panels
• ATS: Buachois Dual Power Automatic Transfer Switch (AC 400V, 2P, 125A)

Problem:

• The inverter periodically alarms and throws an F12 error, indicating a DCDC overcurrent.
• After the alarm sounded a few times, the ATS switch failed (this is the third ATS switch to fail in my system).
• One technician says the inverter is the problem, while another says the ATS switch failed and caused the issue.

Additional Context:

• Local grid electricity is unreliable and often causes power surges when it returns, which I suspect might contribute to the problem.
• I use the ATS switch to connect to the grid as a backup when my batteries are low.
• A technician has suggested installing an RCD main switch to protect against surges and reduce future damage.

I’m unsure how to proceed and would appreciate your insights on the following:

1. Could the inverter be causing the ATS to blow, or vice versa?
2. Would an RCD main switch help protect the system from surges or prevent these issues?
3. Are there other potential causes or solutions I should consider?

Any advice would be greatly appreciated. Thank you!