Description

The ABB TF42-7.6 is an electronic overload relay from ABB’s TF42 series, providing precise and reliable motor overload protection with a current setting range of 4.8–7.6 A. Designed for direct mounting onto compatible ABB AF09 to AF38 contactors, this electronic relay uses a microprocessor-based thermal model to monitor motor current and calculate the thermal state of the motor windings with greater accuracy than conventional bimetallic thermal relays. This enables more precise protection thresholds, faster response to overload conditions, and the ability to provide consistent protection performance independent of ambient temperature variations.

The TF42-7.6 complies with IEC 60947-4-1 and provides Class 10 tripping characteristics. The adjustable current setting dial enables precise calibration to the motor’s rated full-load current within the 4.8–7.6 A range, and built-in phase failure sensitivity ensures the relay responds correctly to single-phasing conditions. The electronic overload relay design provides more stable and repeatable tripping characteristics compared to bimetal relays, which can drift with temperature and may be affected by heating within a crowded panel enclosure. A trip indicator and manual reset function are incorporated as standard.

The TF42-7.6 mounts directly onto compatible ABB AF09 to AF38 contactors via a direct-fit adapter, creating a compact and co-ordinated motor starter assembly within the control panel. Auxiliary contact outputs provide trip feedback for integration with PLC systems, SCADA monitoring, and remote alarm circuits. This relay is used in motor control panels across industrial, building services, water treatment, and process applications throughout Ireland and Europe, providing dependable electronic overload protection for three-phase induction motors in the 4.8–7.6 A range where the enhanced accuracy and stability of electronic protection is required or preferred over thermal relay alternatives.