GoodWe Error 10 — Ground I Failure (earth leakage current)

What it means: The inverter measured more current leaking to earth than its safety limit allows and shut down to protect people, not equipment. GoodWe gives three causes — neutral and ground not properly connected at the AC terminals, leakage from the PV panels to ground when humidity is high, and loss of the utility ground. The first and third are earthing faults in your house wiring; only the second is weather.

Why does GoodWe show 10?

• Neutral and ground cables not well connected at the inverter's AC terminals
• Loss of the utility ground — the earth reference the inverter relies on is simply not there
• Leakage current from the PV array to ground when humidity is high, which is the benign version
• A corroded, undersized or single earth electrode that cannot hold a low resistance in dry soil

The Pakistan factor

Along with error 25, this is the code that defines GoodWe ownership in Pakistan, and neither is really an inverter fault. A single earth rod driven into dry Punjab soil, a distribution board where neutral and earth were never properly bonded, and a back-up circuit wired by whoever quoted lowest will throw 10 for years, and no firmware update fixes a corroded electrode. The seasonal pattern is diagnostic. Monsoon and winter-dawn trips that clear by mid-morning are almost always panel leakage across damp glass and dusty frames. Trips on a dry May afternoon are your earthing. If the house also has water heaters, motor pumps or a tube well on the same earth, treat any tingle as an emergency rather than a quirk.

How to fix it

1. Before anything else. If you or anyone in the house has felt a tingle or a shock from the inverter case, the DB, a tap, a washing machine or any other earthed metal, switch the system off at the AC breaker and call a qualified electrician now. Do not wait, do not test it again, and do not touch the enclosure. Error 10 plus a tingle is a live earthing defect and it is a shock hazard before it is an inverter problem.
2. Log when it happens. GoodWe's own rule of thumb is that if the fault only occurs on humid or rainy days it is due to PV panel leakage, and that version usually clears as the array dries. A fault that fires on a dry, still afternoon is not weather.
3. Do not attempt GoodWe's measurement yourself. Their check is a multimeter reading between earth and the inverter frame on a live system, and it should read close to 0 V. That is a qualified electrician's job on energised equipment.
4. Have your installer take and record that reading. Any voltage between earth and the inverter frame means neutral and ground are not properly connected at the AC terminals — that is the finding, not an opinion. They should also confirm the utility ground is actually present and that the earth electrode is sound.
5. If the earthing is proven good, the reading is clean and 10 still fires on dry days, stop and go to the GoodWe service centre. Do not open the inverter and do not disable or raise any leakage protection to make the alarm go away — that protection is the only thing standing between a DC insulation fault and the people in the house.