Earthing is the most overlooked part of solar installations in Pakistan. Bad earthing does not cause immediate problems — it shows up 2 to 5 years later as component failures, nuisance trips, and in the worst cases fires and electric shocks. Here are the five mistakes I see most often.

Mistake 1: No earth on the panel frames. Every panel frame must be bonded to a proper earth electrode. I have seen installs where the frames are completely floating. If cable insulation breaks down inside a panel, the frame goes live. Anyone cleaning the panels — typically a mali or house worker — is at serious risk of electrocution.

Mistake 2: Using neutral as earth. In older Pakistani buildings, neutral and earth are often tied together at the consumer board. This is technically wrong (they should only be connected at the main earthing point). When solar installers extend this to the inverter's AC output, they create a neutral-earth loop that causes nuisance tripping and accelerated inverter wear.

Mistake 3: Undersized earth conductor. The earth wire from the inverter to the earth electrode should be at minimum 6mm² copper for residential systems up to 10kW. I regularly see 2.5mm² used. Under a fault the earth must carry enough current to trip the MCB — an undersized wire burns before the breaker trips.

Mistake 4: Bad or missing earth electrode. One short copper-coated rod hammered 1 metre into dry Punjab clay is not an effective earth. Soil resistivity in Faisalabad is high, especially in summer. Earth resistance must be below 5 ohms. This requires measurement with a proper earth resistance tester. If your installer cannot give you the measured earth resistance reading at commissioning, it was never tested.

Mistake 5: Battery cabinet not earthed. Dyness, Pylontech, and REPT battery enclosures must be earthed. Under a fault condition the BMS can put voltage on the metal cabinet. Always earth the battery rack the same way as the inverter chassis.

The right approach: run a continuous earth conductor from all panel frames, through the DC combiner, to the inverter earth terminal, then to a properly installed earth electrode. Use crimped lugged terminations, not twisted copper ends. Document the measured earth resistance.

Questions on earthing practice? Post your installation details below and we can discuss.