The LKHT-72.5/S is based on the design of the LKHT-145/S. The 3-pole outdoor high tension SF6 circuit breaker is of the self-extinguishing (auto-puffer) type GCB with an explosion chamber within each pole-assembly for enhanced performance. The pole-assembly housing is filled with SF6 gas, the contacts of the GCB are enclosed within the housing.

During a short-circuit, the energy generated by the arc is redirected into the arc-quenching explosion chamber to quench the arc. Hence the greater the short-circuit the more the energy available to quench the arc. This system reduces the energy required from the operating mechanism to less than half of that required by a conventional SF6 puffer-type circuit breaker. The LKHT-72.5/S is operated by a motor-charged spring operating mechanism type CSM-145, which is the same mechanism used for the LKHT-126/S and LKHT-145/S.