1250 KVA 11 KV Class Distribution Transformer with ON Load Tap Changer (OLTC) make 1250 KVA, 11/0.433 KV,Copper Wound, Oil Immersed, Outdoor Type Distribution Transformer with TappingRange +5% to 10% in Steps of 2.5% by Off Circuit Tap Changer. Energy Efficient Level-1 (3 Star Rating)Vector Group Dyn11 Impedance: 5%.