System Fault Library

Sigenergy SigenStor Fault Codes

Common SigenStor alarms (the 1000-series inverter codes) explained, with what each points to and what to check.

Independent · manufacturer-neutralReviewed June 2026Source: Manufacturer documentationOur methodology
Manufacturer
Sigenergy (SigenStor)
Codes documented
13
Source
Manufacturer documentation
Scope
Reference only

Sigenergy's SigenStor is a newer all-in-one system that stacks the PV inverter, battery, and energy controller in one tower, so its alarms cover the full chain from the DC strings through the battery to the grid connection. Codes are shown in the mySigen app and SigenCloud portal as a four-digit number, where the first digit points to the component: 1000-series = inverter/energy controller, 2000 = battery, 3000 = gateway, 4000 = peripherals, 5000 = EV charger. Most codes also carry a sub-ID (ID1, ID2, etc.) that pinpoints the exact string, phase, or module involved. The list below covers the most common, well-documented 1000-series operational alarms; we have deliberately left out codes we could not verify against authoritative documentation. **Safety note: SigenStor combines high-voltage DC strings, a high-voltage battery, and a grid connection in one enclosure. Treat every alarm as live. Do not open the unit, disturb DC isolators or PV/battery wiring, or touch any AC connection — in Australia that is licensed-electrician (and, for grid work, accredited-installer) territory. Where this product carried a safety recall on some single-phase EC models, follow your installer's and Sigenergy's instructions rather than self-servicing.

Key takeaways
  • 13 Sigenergy (SigenStor) fault and alarm codes, documented in plain English.
  • Compiled from manufacturer documentation — independent and not affiliated with Sigenergy (SigenStor).
  • Codes involving DC/AC isolators, wiring or opening the unit are licensed-electrician work — when in doubt, call your installer.

13 of 13 codes

  • 1002

    Low insulation resistance (ISO fault)

    The inverter has measured low insulation resistance on the PV (DC) side — meaning the system is detecting a possible leakage path to earth. Common triggers are moisture ingress in a connector or cable, a damaged DC cable, or a string partially shorting to the protective earth (PE). It often appears in the early morning when humidity is highest and may self-clear as things dry out.

    What to do

    If it self-clears as the day warms up, it was most likely transient damp. If it persists or recurs, do not start pulling DC plugs apart yourself — the strings can sit at hundreds of volts. Log the code in the mySigen app and have your installer or a licensed electrician inspect the DC cabling, connectors, and earthing.

  • 1003

    Inverter over-temperature

    The inverter has exceeded its safe internal operating temperature and has throttled or shut down to protect itself. Usual causes are high ambient temperature, the unit sitting in direct sun, or restricted airflow/poor ventilation around the tower.

    What to do

    Make sure nothing is blocking airflow around the unit and that it is not baking in direct afternoon sun (a sail or shade can help on a hot Australian roof or wall). It should resume automatically once it cools. If it keeps tripping in normal conditions, contact your installer — do not open the enclosure.

  • 1006

    String input overvoltage (PV)

    The DC voltage from a PV string (the sub-ID identifies which string — e.g. ID1 = String 1) is above the inverter's maximum allowed input voltage. This almost always means too many panels were wired in series for that string, and the problem shows up worst on cold, bright mornings when panel voltage peaks.

    What to do

    This is a design/wiring issue, not something you can clear from the app. Have your installer review the string sizing and panel count per string against the inverter's maximum input voltage. PV/DC work is licensed-electrician territory — do not rewire strings yourself.

  • 1009

    AFCI fault (DC arc detected)

    The arc-fault circuit interrupter has detected what looks like an electrical arc on a PV string (the sub-ID flags which string). This is a genuine fire-safety feature — arcs are usually caused by a damaged DC cable, a loose or corroded connector, or a poor contact at a string terminal.

    What to do

    Treat this seriously. Note which string (the sub-ID) is flagged. You can attempt one clear/reset via the mySigen app, but if it returns, stop and call your installer — the DC side may have a damaged cable or loose connector that needs a licensed electrician to inspect for burn marks. Do not open connectors on a live string yourself.

  • 1010

    Grid power outage / grid power failure lock

    The inverter has detected that the grid has gone away — either an actual blackout or the AC isolator/main switch being turned off (ID1). A persistent or repeated loss can put the system into a grid-failure lock state (ID2). With backup configured, the system transfers to battery/backup; otherwise it stops exporting and waits.

    What to do

    Normally informational — the system reconnects on its own once the grid returns. Check whether there is a local blackout or whether an AC switch has been left off. If the grid is clearly present but the alarm stays locked on, have your installer check the AC connection rather than resetting switches yourself.

  • 1011

    Grid overvoltage (Level I / II / III)

    The grid voltage at your connection point has risen above the allowed protection threshold, so the inverter disconnects to protect itself and comply with grid rules. Level I is mildest, Level III most severe. This is one of the most common alarms in Australia, especially around midday in areas with lots of rooftop solar pushing voltage up.

    What to do

    This is almost always a network/grid condition, not a fault in your unit — it should reconnect automatically when voltage settles. If it happens repeatedly and curtails your solar, raise it with your installer and your DNSP (distributor); voltage limits and any volt-watt/volt-var settings should only be changed by your accredited installer.

  • 1012

    Grid undervoltage (Level I / II / III)

    The grid voltage has dropped below the protection threshold, so the inverter disconnects until it recovers. It usually reflects a weak or sagging grid supply rather than an inverter fault, and is more common on long rural feeders or during high-demand periods.

    What to do

    Generally clears by itself once grid voltage recovers. If it persists or happens often, report it to your installer and electricity distributor — there may be a supply-side issue. No user reset of switches or settings.

  • 1013

    Grid overfrequency (Level I / II / III)

    The grid frequency has risen above the allowed threshold and the inverter has disconnected per grid protection rules. This is a grid-side condition, not an internal fault, and usually clears within seconds.

    What to do

    Self-recovers when frequency returns to normal. Persistent or frequent trips should be reported to your installer/distributor. Protection thresholds are set to local grid standards and are not for the owner to change.

  • 1014

    Grid underfrequency (Level I / II / III)

    The grid frequency has fallen below the allowed threshold and the inverter has disconnected to comply with grid protection requirements. Like overfrequency, it is a grid-side event that normally clears within seconds.

    What to do

    Self-recovers once frequency stabilises. If it recurs, report it to your installer and distributor; do not alter protection settings.

  • 1017

    Leak current out of limit

    The inverter has measured residual/leakage current above its safety threshold. It is often transient — caused by damp conditions or a momentary disturbance — and the system typically recovers once the environment settles.

    What to do

    If it self-clears, it was likely a transient damp-weather event. If it recurs frequently, there may be an insulation or earthing issue on the DC or AC side (moisture ingress, damaged cable, or a faulty RCD) — log it and have your installer or a licensed electrician investigate. Do not open the unit or disturb wiring yourself.

  • 1018

    Communication fault (4G / CAN / meter / gateway)

    A communication link inside the system has dropped — for example the 4G/monitoring module (ID1), the battery CAN bus (ID2), the energy meter (ID3), or the gateway (ID4). The sub-ID identifies which link. Monitoring or energy-management features may stop working while it is active even if power flow continues.

    What to do

    A power-cycle (following your installer's documented procedure) often restores communications. If it keeps recurring, a connector may be loose or a module faulty — have your installer reseat connectors and check the wiring rather than opening the enclosure yourself.

  • 1022

    EPO / emergency stop activated

    The emergency power-off (EPO) input has been triggered — typically because someone pressed the emergency-stop button (or, on some installs, a shutdown command in the mySigen app). The system stays shut down for safety until the EPO is released.

    What to do

    Confirm it is safe to restart, then release/reset the emergency-stop button (or clear the shutdown in the app) to clear the alarm. If the EPO was pressed because of a genuine emergency (smoke, fire, fault), leave it tripped and contact your installer or emergency services first.

  • 1023

    Neutral disconnected / abnormal AC wiring

    The inverter has detected a problem with the AC wiring — most commonly a neutral conductor that is disconnected or has worked loose inside the inverter (ID1), or otherwise abnormal AC wiring (ID2). A poor neutral connection can be a safety hazard.

    What to do

    This is an AC wiring issue and must be handled by a licensed electrician — do not attempt to inspect or re-terminate AC wiring yourself. Have your installer power down safely and check the neutral and AC terminations.

Sources

Good to know

Frequently asked

Where do these Sigenergy fault codes come from?
We compile them from publicly available Sigenergy inverter documentation and field references, then rewrite each entry in plain English. Solar Analytica is independent and not affiliated with Sigenergy.
Can I clear these faults myself?
Some clear automatically once conditions return to normal. Anything involving DC isolators, AC switches, wiring or opening the unit is licensed-electrician work — if in doubt, contact your installer rather than working on a live system.
My exact code isn't listed — why not?
Firmware and model variants differ, and manufacturers occasionally revise their codes. We document the most common ones; if yours isn't here, check your inverter's manual or ask your installer.
How current is this reference?
Last reviewed June 2026. We revise it when the underlying manufacturer documentation changes.