100042 on an AlphaESS SMILE-G3: Output_short - backup (off-grid) output short circuit
Short answer
On an AlphaESS inverter, 100042 means: Output_short - backup (off-grid) output short circuit. The inverter keeps running with some functions stopped. An engineer is needed to fix the cause.
Reviewed 24 September 2026 · 1 source
What it means
The manual says: Output_short - backup (off-grid) output short circuit.
Likely causes:
- Short circuit or wiring fault on the off-grid/backup output.
Is it safe?
Switch the inverter off at its isolator and call an engineer.
| Does the inverter stop? | Partly |
|---|---|
| Severity | Fault — needs a manual reset once the cause is fixed |
| Engineer needed? | Yes |
The inverter keeps running with some functions stopped.
Resetting itself: restart after cause removed.
Manual reset: Restart of the inverter by installer (power-down/power-up sequence) if it does not clear.
What you can check
- Read the code in the AlphaCloud app/web portal (or the LED pattern on the unit) and note it with the time. Check the inverter's AC isolator and the consumer-unit breaker for the inverter are ON. Report persistent or repeating codes to your installer - AlphaESS says 'call the service' if it does not clear.
What the engineer will check
- Test impedance of the off-grid output with a multimeter, check backup-circuit wiring and connected loads; restart.
Who to ask for: MCS PV/battery installer familiar with AlphaESS.
Certification: MCS-certified solar PV installer (MIS 3002) or competent electrician (BS 7671 / Part P in England & Wales); DC work only by PV-trained installer.
What you might notice
Sources
- Installation, Operation & Maintenance Manual of SMILE-G3-S3.6/S5/B5 (V01, 14.08.2023) ↗ · V01 · page p.85 (printed) · Reviewed 24 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 24 September 2026