ABB TF42-20 Thermal Overload Relay

ABB TF42-20 Thermal Overload Relay is an economical electromechanical protection device for the main circuit of motor-control systems, designed to be used with ABB contactors in industrial drives. It covers a 16–20 A full-load current range and is rated for up to 690 V AC on the main circuit, with a trip class of 10 to provide reliable overload protection. Wiring is specified for ≤20 A applications using conductors 0.75–4 mm² in cross-section (stranded or flexible variants, with or without ferrule), and the terminals have a tightening torque of 1.5–2.5 Nm. This TF42-20 variant is identified by part number 1SAZ721201R1049 and is part of ABB's TF42 thermal overload relay family, designed to protect motors in industrial drive and panel installations.