3701 on a SMA Solar Technology AG Sunny Boy: The inverter has detected a residual current through brief grounding of the PV module
Short answer
On a SMA Solar Technology AG inverter, 3701 means: The inverter has detected a residual current through brief grounding of 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 residual current through brief grounding of the PV module.
Part involved: insulation / residual current (earth fault).
When it shows: The inverter has detected a residual current through brief grounding of 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 93 · Reviewed 24 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 24 September 2026