Grid Relay Fault on a SolaX Power SolaX X1-Hybrid G3: Grid relay fault (manual text says 'EPS Relay Fault')
Short answer
On a SolaX Power inverter, Grid Relay Fault means: Grid relay fault (manual text says 'EPS Relay Fault'). 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: Grid relay fault (manual text says 'EPS Relay Fault').
Part involved: Grid relay / relay test.
Likely causes:
- As described in manual.
Is it safe?
| Does the inverter stop? | Yes |
|---|---|
| Severity | Fault — needs a manual reset once the cause is fixed |
| Engineer needed? | Yes |
The inverter stops until the fault clears or is reset.
Resetting itself: may clear at next start if caused by N-PE issue.
Manual reset: installer.
What you can check
- Read and note the exact code and time from the inverter display or app (screenshot).
- Check the solar/battery AC isolator and the consumer-unit breaker/RCD are ON (do not reset a breaker that trips again immediately).
- Where the SolaX manual says 'press the ESC key to restart the inverter', a homeowner can do that on the display. Steps that say 'disconnect PV+/PV-/battery' are for the installer only.
What the engineer will check
- Check N and PE connections and N-PE voltage.
- Restart.
- Replace inverter if relay test keeps failing.
Who to ask for: PV installer / electrician.
Certification: Electrician competent in grid-connected PV (BS 7671 Section 712; IET Code of Practice for Grid-connected Solar PV), ideally the original MCS-certified PV installer; brand-approved/trained installer to keep manufacturer warranty.
What you might notice
Sources
- X1-Hybrid G3 User Manual (EN) ↗ · page PDF p.34-35 · Reviewed 24 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 24 September 2026