The rotary handle is used for operating resp. switching ON/ OFF MCB's 5SY/5SL/5SP and isolators 5TL1 and 5TE2 without opening the door of the switchboard. Siemens CFSH10R4N Door Mounted Heavy Duty. Isolation switches in distribution boxes ensure electrical safety by disconnecting circuits for maintenance, preventing shocks, aiding compliance, and improving system reliability. What Is an Isolation Switch? Ready to Upgrade Your Electrical Safety? What Is an Isolation Switch? An isolation switch. ABB rotary handles are essentially a switch that can be used to control different circuit operations using rotation. Each position corresponds to a different circuit path, making rotary switches ideal for applications that require multiple selection options from a single. Padlockable with 3 padlocks in the OFF-position, door interlock in the ON-position.