The Eaton TF42-24 is a 3-pole thermal bimetallic overload relay with a 20.0 to 24.0 Amp adjustment range, Trip Class 10, and selectable manual or automatic reset. It is designed for use with AF Series contactors in the AF9 through AF38 frame sizes — meaning it mounts directly to those contactor bodies without additional hardware, saving panel space and wiring time. That is the standard for standard-duty motor starting — fast enough to protect the motor winding during a stalled-rotor condition but slow enough to ride through normal inrush. For a 24 A motor load, set the dial to the motor nameplate FLA; the 20-24 A window covers NEMA frame sizes up to about 7.5 HP at 460 V.
Integration with AF contactors
The TF42-24 snaps directly onto AF9 through AF38 contactors — no separate mounting kit or bus bar required. The thermal bimetal element is in the power path between the contactor output and the motor leads, so the wiring sequence is line → contactor → overload relay → motor. The selectable manual/automatic reset is a DIP-style lever on the front face; set it to manual for applications where an automatic restart after a trip could be a safety hazard (conveyors, presses), and automatic for remote or unattended installations like HVAC or pump stations.