ABB TF42-29 Thermal Overload Relay, 23-29 A, 3-Pole, Class 10, 690 V AC, Screw Terminals, Direct Contactor Mounting

In industrial motor control panels, electricians and maintenance engineers rely on the ABB TF42-29 thermal overload relay to protect three-phase motors from overheating due to overload or phase loss. This relay, part of the TF42 series, is designed for direct mounting onto ABB contactors such as AF09 to AF40, providing a compact and reliable protection solution. With an adjustable current range of 23 to 29 A, it suits a wide variety of motor sizes in pumps, fans, conveyors, and compressors.

Key specifications

• Rated operational current range: 23 - 29 A
• Number of poles: 3
• Tripping class: Class 10
• Rated operational voltage: 690 V AC
• Rated insulation voltage: 690 V
• Rated impulse withstand voltage: 6 kV
• Auxiliary contacts: 1 NO + 1 NC
• Connection type: Screw terminals (main and auxiliary)
• Mounting: Direct contactor mounting
• Reset: Manual and automatic
• Phase loss sensitivity: Yes
• Degree of protection: IP20 (terminals)
• Ambient operating temperature: -25 to +60 °C
• Standards: IEC/EN 60947-4-1, UL 60947-4-1, CSA 60947-4-1

Why choose it

The ABB TF42-29 offers dependable thermal protection with precise adjustment and phase loss detection, ensuring motor longevity and reducing downtime. Its Class 10 tripping characteristic provides fast response to overloads, while the dual reset modes allow flexibility in operation. The relay's robust construction and compliance with international standards make it a trusted choice for industrial applications.

Ideal use cases

• Protecting three-phase motors in industrial machinery
• Pumps, fans, conveyors, and compressors
• Motor control panels requiring reliable overload protection

Good to know

The TF42-29 is part of ABB's TF42 series and is compatible with ABB contactors AF09 to AF40 and A9 to A40. It features screw terminals for secure connections and can be reset manually or automatically. The relay operates in ambient temperatures from -25 to +60 °C and can be stored from -40 to +70 °C. Power loss per pole is 0.8 W.