Siemens 3TF48 USNT Contactor

Siemens 3TF48 USNT Contactor is a 3-pole motor-contactor from the Siemens 3TF48/49 family designed to switch three‑phase power for industrial motors. It is rated to handle up to 75 A and up to 600 V AC (AC-3) in standard 50/60 Hz service, making it suitable for direct-on-line motor control in conveyors, pumps, fans, and machinery control panels. The USNT designation identifies a specific coil/terminal variant used on the 3TF48/49 contactors; coil voltage options for the 3TF48/49 family include 110/120 VAC and 230 VAC, with examples such as 3TY7483-0AK6 (AC 110/120 V) and 3TY7483-0AP0 (AC 230 V). The contactor commonly includes two normally open and two normally closed auxiliary contacts to support basic interlocking and control logic. Replacement contact kits and accessory blocks for auxiliary contacts are available from Siemens and approved aftermarket suppliers, aiding maintenance and expansion of the control circuit.