Siemens 3TB4717‑OA is a manual motor starter used in industrial and commercial electrical systems to start and stop motors and provide basic motor overload protection. It combines a disconnect switch with a thermal overload trip mechanism that opens the circuit automatically if the motor draws excessive current for too long. Operators can manually turn the starter on or off, and the overload element helps prevent motor winding damage by interrupting power during overcurrent conditions. This type of starter is commonly mounted in motor control panels and distribution equipment where simple motor control and protection are needed. It is suitable for moderate horsepower motors and can be used with or without additional contactors depending on the application.