I will appreciate if someone give me code requirement for the application of manually operated 138KV Disconnect Switches which are being applied on each side of SF6 Circuit Breaker. One Disconnect Switch is connected to 138KV Transmission Line and second Disconnect Switch is connected to HV side of Generator Step-up Transformer (13.8KV/138KV, 66 MVA). What are the risk to the operator operating and or damage to 138KV line switche with SF6 Circuit Breaker in open position and line energized.