Siemens 3UA1000-1J Three Phase Motor Thermal Overload Relay

Siemens 3UA1000-1J is a three‑phase motor thermal overload relay from the 3UA family, designed to protect AC motors by interrupting circuit current when the windings overheat due to overload or impedance faults. This model is specified for a current setting range of 6.3 to 10 A, aligning with other 3UA1J variants used for motors within that envelope and intended for integration into Siemens starter assemblies. The 3UA line is engineered for motor protection across voltages up to 690–1000 V and currents reaching several hundred amperes, making it suitable for a broad spectrum of industrial motors. As a thermal‑delay relay, it responds to sustained overcurrent to shield windings from damage and to enable coordinated protection with Siemens contactors in IEC motor control circuits. Typically mounted on standard starter frames, the 3UA1000-1J variant is used in applications such as pumps, fans, conveyors, and other three‑phase motors in manufacturing environments where dependable overload protection is required and where Siemens protection gear is already employed.