What you will see
- Error 303 at start-up
- Often after electrical work, a meter change or a new earth pit
Why it happens
A broken or dry earth, a loose neutral at the board or the meter, or swapped wires all raise neutral-to-earth voltage.
Diagram
Neutral and earth must stay close
Healthy
NeutralSound
→EarthConnected
→InverterRuns
Fault
Loose neutral or poor earthVoltage between them
→InverterError 303
Treat it as a safety fault.
What you can check yourself
- Note any recent electrical work
- Find your earthing test record if you have one
What not to do
- Do not run without earth
- Do not open the board or terminal covers
When to call us
- Measure neutral-earth voltage
- Test the earth pit and continuity
- Check AC wiring order
Earthing in older houses
Dry earth pits and loose neutrals are common in older Faisalabad and Lahore homes. We test earthing and give you a written record.
Send us
the alarm photo and details of recent electrical work