CT LN Reversed on a Growatt SPH 3000-6000TL BL-UP: CT LN Reversed - L and N of SP-CT reversed / SP-CT PE wire
Short answer
On a Growatt inverter, CT LN Reversed means: CT LN Reversed - L and N of SP-CT reversed / SP-CT PE wire. The inverter keeps running with some functions stopped. An engineer is needed to fix the cause.
Reviewed 24 September 2026 · 1 source
What it means
The manual says: CT LN Reversed - L and N of SP-CT reversed / SP-CT PE wire.
Part involved: Energy meter / CT clamp communication.
Likely causes:
- L and N of SP-CT reversed / SP-CT PE wire.
Is it safe?
| Does the inverter stop? | Partly |
|---|---|
| Severity | Warning |
| Engineer needed? | Yes |
The inverter keeps running with some functions stopped.
Resetting itself: yes - clears when communication is restored.
Manual reset: no.
What you can check
- Read and note the exact code and time from the inverter display or app (screenshot).
- Check the meter's display is lit (look only).
- Note any recent electrical work near the meter/consumer unit.
- 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 meter RS485/Modbus wiring polarity and termination.
- Check CT orientation (arrow towards grid/house per manual) and seating.
- Check meter address/baud settings.
- Check export-limit setting (G99) - some inverters stop if export control is on and meter lost.
Who to ask for: PV/battery installer.
Certification: Installer or electrician for meter/CT/comms cabling; homeowner can handle Wi-Fi/router issues.
What you might notice
Sources
- Growatt SPH 3000-6000TL BL-UP User Manual EN 202512 ↗ · EN 202512 · page PDF p.61 · Reviewed 24 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 24 September 2026