Siemens 3TF3400-0A USNT Industrial Control Relay Module

Siemens 3TF3400-0A USNT is a CRLOF3 reversing contactor module that provides forward/reverse control for 3‑phase motors in industrial control panels. As part of the 3TF motor-starter family, this 3‑pole device is designed to switch motor circuits reliably in starter configurations used in conveyors, machine tools, and similar equipment. Coil variants are offered for AC operation at voltages such as 110 V, 230 V, and 415 V, enabling use with a range of common industrial control voltages. The unit carries an Ie AC3 rating up to 32 A and supports operation up to 415 V, with typical motor power ratings around 15 kW at 415 V (50 Hz) depending on duty. The 3TF3400-0A identification appears in Siemens datasheets as a reversing-contactor option in the CRLOF3 family, underscoring its role in bidirectional motor control. For procurement, distributors list this exact model as Siemens 3TF3400-0A, confirming its function as a dedicated reversing contactor module rather than a generic relay module. This makes it suitable for panel builders who need a compact, relay-based solution to reverse motor direction and streamline control logic in automation layouts.