Solar · Error codes · SMA Solar Technology AG
1302SMA Solar Technology AG · Sunny Boy (SB 1.5-6.0)
1302 on a SMA Solar Technology AG Sunny Boy: L or N not connected
Short answer
On a SMA Solar Technology AG inverter, 1302 means: L or N not connected. 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: L or N not connected.
Part involved: AC connection / grid supply.
When it shows: L or N not connected.
Likely causes:
- SMA corrective measures: Ensure that the line conductors are connected. Ensure that the miniature circuit breaker is switched on. Ensure that the AC cable is not damaged and that it is connected correctly.
Is it safe?
| Does the inverter stop? | Yes |
|---|---|
| Severity | Fault — clears by itself when the condition goes |
| Engineer needed? | Yes |
The inverter stops until the fault clears or is reset.
Resetting itself: yes.
Manual reset: Automatic when condition clears.
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.
- Check the solar inverter's circuit breaker (MCB) in the consumer unit / AC isolator is switched on - SMA's corrective measures for this event start with 'Ensure that the miniature circuit breaker is switched on'.
- Check whether there is a power cut in your area.
- If it happens once and the inverter resumes feeding in on its own, no action is needed; if the event keeps recurring, contact your installer.
What the engineer will check
- Check AC cable for damage and correct termination; verify L and N connected; confirm country data set; measure grid voltage at the connection point; DNO liaison if grid voltage is out of range.
Who to ask for: Electrician / PV installer.
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 91 · Reviewed 24 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 24 September 2026