HESP series hybrid inverters (single-phase 4-12 kW and three-phase 8-12 kW)
SRNE 50 error code
Grid under-voltage: grid voltage is below the lower limit of the selected grid standard, so the inverter disconnects from the grid.
Likely causes
- Weak grid or long low-voltage feeder
- Voltage drop on undersized AC input cable
- Grid recovering after an outage
- Grid standard selected does not match the local supply
Checks to run, in order
- 1Measure the AC input voltage at no load and under load
- 2Check AC cable size and length for voltage drop
- 3Compare with the selected grid standard window
- 4Check the voltage at the main board for comparison
Fixes
- Wait for the supply to recover
- Upgrade undersized AC input cable
- Set the correct grid standard for the site
When to escalate
If the voltage at the inverter terminals is inside the window while the fault persists, the distributor should inspect the measurement circuit.
Fix it with the right tools
Check the system around the fault before replacing parts: load, battery bank, PV string and commissioning settings. If you need a second opinion, send the code and your inverter model to our team.
Before you open the inverter
- Isolate both the AC and DC sides, then confirm the display is dead before touching terminals.
- Use insulated tools and one hand where possible. DC arcs do not self-extinguish like AC.
- If you see burnt terminals, swollen cells, leaking electrolyte or a burning smell, stop and escalate instead of resetting the fault.
Questions installers ask
What does SRNE 50 mean?
Grid under-voltage: grid voltage is below the lower limit of the selected grid standard, so the inverter disconnects from the grid.
How do I fix SRNE 50?
Wait for the supply to recover Upgrade undersized AC input cable Set the correct grid standard for the site
When should I escalate SRNE 50?
If the voltage at the inverter terminals is inside the window while the fault persists, the distributor should inspect the measurement circuit.
Can I reset SRNE 50 myself?
Only after isolating the AC and DC sides and running the checks above. If SRNE 50 returns immediately, stop resetting it and escalate; a repeating fault usually points to a real circuit, battery or hardware problem.
Which models show SRNE 50?
SRNE 50 is documented for HESP series hybrid inverters (single-phase 4-12 kW and three-phase 8-12 kW). Confirm the code on your own unit's display or manual before ordering parts.
More SRNE error codes
- SRNE 01Battery undervoltage alarm: the battery voltage has fallen below the [Batt. Under volt. alarm] value under Battery Setup, and the alarm does not by itself stop the output.
- SRNE 02Battery discharge average current overcurrent, detected by software (BatOverCurrSw); the inverter limits or stops discharge.
- SRNE 03Battery not connected (BatOpen): the inverter cannot see a battery on the DC side and stops the output.
- SRNE 04Battery undervoltage stop-discharge (BatLowEod): the battery has reached the low-voltage cut-off and the inverter has stopped discharging.
- SRNE 05Battery overcurrent detected by hardware protection (BatOverCurrHw); the inverter shuts the output down.
- SRNE 06Charging overvoltage protection (BatOverVolt): battery voltage rose above the over-voltage cut-off and charging was stopped.
Guidance reviewed 17 October 2026 by the Mishka Energy installer team. Error codes vary by brand, model family and firmware; confirm against the manufacturer manual.
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