Technical Support

Hello SunSynk Technical Support Community,

I’m encountering a recurring fault issue on my SunSynk hybrid inverter and would like to ask for technical advice from experienced users or installers.

Fault codes observed:

• Grid Lost

• AC Over Voltage (appears occasionally, especially during peak grid hours)

System details:

• SunSynk Hybrid Inverter

• Grid + Solar + Battery system

• Grid voltage in my area is unstable at certain times of the day

• Firmware is up to date

Issue description:The inverter works normally most of the time, but intermittently shows Grid Lost or AC Over Voltage faults. When this happens:

• The inverter disconnects from the grid

• System switches to battery/solar mode

• After a short time, grid reconnects automatically

Grid voltage readings sometimes rise above the normal range before the fault appears.

What I’ve checked so far:

• Grid voltage and frequency limits are set according to local standards

• AC wiring and grid connection are secure

• No visible damage or loose connections

• Issue happens even with low load

Questions for the community:

1. What grid voltage thresholds usually trigger AC Over Voltage on SunSynk inverters?

2. Can unstable utility supply alone cause frequent Grid Lost faults even if wiring is correct?

3. Are there recommended settings or protections to reduce unnecessary grid disconnections?

4. Has anyone resolved this issue by adjusting grid parameters or using external voltage protection devices?

I hope this discussion can help clarify whether this is mainly a grid-quality issue, a configuration issue, or Golf Hit something that requires installer or utility-side action.

Thank you for your time and support.