Calculate the insulation resistance value HV side for 1600 KVA, 20 KV/400 V three-phase transformer. Let the value of constant (C) be 1.5 for the oil-filled T/C with the oil tank at 20°C.
1
187.5 mega ohm
2
18.75 mega ohm
3
15 mega ohm
4
750 mega ohm