What size earth is required from the incomer to the earth bar if the mains tails from the transformer are 4 x 630mm 2 per phase and 2 x 630mm 2 Neutral/Earth
A Petrol filling Station has a main TNC - S supply it also has a main earth terminal with link connected to two earth electrodes.The value of Ze with only the earth electrodes connected is 16.0 ohm and a suitable RCD is fitted. As well
