3501 on a SMA Solar Technology AG Sunny Boy: The inverter has detected a ground fault in the PV module
Short answer
On a SMA Solar Technology AG inverter, 3501 means: The inverter has detected a ground fault in the PV module. The inverter stops until the fault clears or is reset. An engineer is needed to fix the cause.
Reviewed 24 September 2026 · 1 source
What it means
The manual says: The inverter has detected a ground fault in the PV module.
Part involved: insulation / residual current (earth fault).
When it shows: The inverter has detected a ground fault in the PV module.
Likely causes:
- SMA corrective measures: Check the PV system for ground faults.
Is it safe?
| Does the inverter stop? | Yes |
|---|---|
| Engineer needed? | Yes |
The inverter stops until the fault clears or is reset.
Resetting itself: unknown.
Manual reset: See engineer checks.
What you can check
- Read the event number and message in the SMA Energy app / Sunny Portal (ennexOS) or the inverter's web interface and note the date/time for your installer. A red LED on the inverter means an event has occurred.
- Do not touch the panels, cables or inverter enclosure - an earth (ground) fault may make exposed parts live. Contact your installer.
- Note whether it happens mainly after rain or in the morning dew - this helps the installer.
What the engineer will check
- Check the PV system for ground faults per SMA section 'Checking the PV System for Ground Faults' (insulation resistance measurement per string, damaged cables/connectors, water ingress, module defects); check any RCD type/setting.
Who to ask for: MCS PV installer with insulation-resistance test equipment.
Certification: Qualified electrician (BS 7671; MCS-certified PV installer for work on the PV array/DC side).
What you might notice
Sources
- Operating manual SUNNY BOY 3.0/3.6/4.0/5.0/6.0 ↗ · SBxx-1AV-41-BE-en-21 Version 2.1 · page 92 · Reviewed 24 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 24 September 2026