SIZE OF EARTH LEADS

SIZE OF EARTH LEADS
For transformer Neutral point Earthing
Transformer rating                kVA	Electrolytic bare copper conductor or strip	Insulated (PVC) Single core stranded aluminium	Galvanized Iron conductor or strip
50 & Below	8 SWG	16 sq.mm	25mm x 3mm
75	8SWG	25 sq.mm	40mm x 6mm
100	4SWG	35 sq.mm	40mm x 6mm
150	2SWG	70 sq.mm	40mm x 6mm
200	25mm x 1.5mm	95 sq.mm	40mm x 6mm
250	25mm x 3mm	150 sq.mm	40mm x 6mm
300	25mm x 3mm	225 sq.mm	40mm x 6mm
500	25mm x 6mm	300 sq.mm	40mm x 6mm
750	25mm x 6mm	300 sq.mm	50mm x 6mm
Note : Above 500 kVA only Copper / Aluminium strip to be used. Above 750 kVA size of earth lead to be determined as per IS : 1888/1967