HESP series hybrid inverters (single-phase 4-12 kW and three-phase 8-12 kW)
SRNE 26 error code
Relay short / AC output backfeeding to the bypass AC input (RlyShort): the AC input relay is stuck or output voltage is reaching the AC input.
Likely causes
- Welded AC input relay
- Output wiring tied to the AC input
- Backfeed from a generator connected to the output
- Relay driver circuit failure
Checks to run, in order
- 1With the inverter off and the AC input isolated, check for voltage on the AC input terminals
- 2Verify the output and input circuits are not interconnected
- 3Check for a generator or other source connected on the output side
- 4Confirm the wiring against the manual's terminal diagram
Fixes
- Correct any input/output interconnection
- Replace the relay board through the distributor
- Restart only after the wiring is verified
When to escalate
A welded relay is not field-repairable, and backfeed is a shock hazard: isolate the unit and call the distributor immediately.
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 26 mean?
Relay short / AC output backfeeding to the bypass AC input (RlyShort): the AC input relay is stuck or output voltage is reaching the AC input.
How do I fix SRNE 26?
Correct any input/output interconnection Replace the relay board through the distributor Restart only after the wiring is verified
When should I escalate SRNE 26?
A welded relay is not field-repairable, and backfeed is a shock hazard: isolate the unit and call the distributor immediately.
Can I reset SRNE 26 myself?
Only after isolating the AC and DC sides and running the checks above. If SRNE 26 returns immediately, stop resetting it and escalate; a repeating fault usually points to a real circuit, battery or hardware problem.
Which models show SRNE 26?
SRNE 26 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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