Solar · Error codes · Solis
GRID-INTF.Solis · S6-GR1P-S single-phase string inverter
GRID-INTF. on a Solis S6-GR1P-S single-phase string inverter: AC hardware overcurrent (grid interference)
Short answer
On a Solis inverter, GRID-INTF. means: AC hardware overcurrent (grid interference). The inverter stops until the fault clears or is reset.
Reviewed 24 September 2026 · 1 source
What it means
The manual says: AC hardware overcurrent (grid interference).
Part involved: AC side.
Likely causes:
- Poor AC connection; grid issue.
Is it safe?
| Does the inverter stop? | Yes |
|---|---|
| Severity | Fault — clears by itself when the condition goes |
The inverter stops until the fault clears or is reset.
Resetting itself: yes.
Manual reset: Restart; contact service.
What you can check
- Read the full code and message on the inverter screen or in the SolisCloud app and note the date/time for your installer.
- Check the inverter's AC isolator next to the inverter and the solar/battery breaker in the consumer unit are ON (do not reset a breaker that trips again - call your installer).
What the engineer will check
- Check AC connection; restart.
Who to ask for: Qualified electrician / MCS PV installer.
Certification: None for homeowner checks; any grid-protection setting change needs installer and DNO consent (G98/G99).
What you might notice
Sources
- User Manual for S6 Series Grid Inverter S6-GR1P(2.5-6)K-S ↗ · Version 1.1 · page 43 · Reviewed 24 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 24 September 2026