The on-load tap changers were first manufactured in the 60's by CG. These tap changers have experienced different outline improvements to improve their products to satisfy user requirements. As a team with M/s.fuller Electric Co - UK, the OLTC began with the "F" series tap changers.
The OLTC complies with IEC, IS, and BS standards. It is a high-speed resistor type intended for use with 3ph distribution substation transformer. It can be bolted directly to a port spine on the transformer. It operates with a voltage up to 72kV with a current up to 300A.