Error 302 on a Growatt inverter: No AC connection
Short answer
On a Growatt inverter, Error 302 means: No AC connection. The inverter stops until the fault clears or is reset. The wording differs by model range — each is shown below.
Reviewed 24 September 2026 · 2 sources
What it means
On the MIN 2500-6000TL-X
The manual says: No AC connection.
Part involved: Loss-of-mains / anti-islanding.
Likely causes:
- AC breaker off.
- Power cut.
- AC wiring.
On the SPH 3000-6000TL BL-UP (48 V battery hybrid)
The manual says: No AC Connection (No Utility).
Part involved: Loss-of-mains / anti-islanding.
Likely causes:
- No AC Connection (No Utility).
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 - restarts after the reconnection time once mains returns.
Manual reset: no.
What you can check
- Read and note the exact code and time from the inverter display or app (screenshot).
- Check whether there is a power cut (other lights/sockets, DNO 105 service).
- Check the solar/battery AC isolator and the consumer-unit breaker/RCD are ON (do not reset a breaker that trips again immediately).
- Growatt's manual says 'restart inverter'. A homeowner can switch the inverter off and on at its AC isolator/breaker; leave DC switching to the installer unless the manual step says to switch DC off immediately (Error 202).
What the engineer will check
- Check AC isolator, breaker and terminations at the inverter.
- Measure L-N voltage at inverter terminals.
- Check neutral connection.
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
- Growatt MIN 2500-6000TL-X Installation & Operation (User) Manual, general EN 2022-06 ↗ · EN 202206 · page PDF p.22 · Reviewed 24 September 2026
- Growatt SPH 3000-6000TL BL-UP User Manual EN 202512 ↗ · EN 202512 · page PDF p.63 · Reviewed 24 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 24 September 2026