ABB TF42-3.1 Thermal Overload Relay, 2.4-3.1 A, 690 V AC, 3-Pole, Class 10, Screw Terminals 1SAZ721201R1033

In motor control panels across industrial facilities, the ABB TF42-3.1 thermal overload relay safeguards three-phase motors by disconnecting power when excessive current is detected. Set between 2.4 and 3.1 A, it matches motors in that range and mounts directly onto ABB AF09-AF38 contactors or as a standalone unit. The relay responds to phase loss and includes both manual and automatic reset options, with one normally open and one normally closed auxiliary contact for status signalling.

Key specifications

• Rated operational current range: 2.4 - 3.1 A
• Rated operational voltage: 690 V AC
• Number of poles: 3
• Tripping class: Class 10
• Mounting: Direct to contactor (AF09-AF38) or standalone
• Degree of protection: IP20
• Auxiliary contacts: 1 NO + 1 NC
• Connection type: Screw terminals
• Temperature compensation: -25 to +60 °C
• Standards: IEC/EN 60947, UL 60947, CSA 22.2 No. 60947

Why choose it

Engineered for reliable motor protection, the TF42-3.1 combines precise thermal sensing with phase failure sensitivity to prevent damage from overloads and single-phasing. Its compact design simplifies panel layout, while the direct-to-contactor mounting reduces wiring effort. The wide ambient temperature range and robust construction ensure consistent performance in demanding environments.

Ideal use cases

• Protecting small three-phase motors in conveyors, pumps, and fans
• Retrofitting existing ABB contactor installations
• Standalone overload protection in custom control panels
• Applications requiring manual or automatic reset flexibility

Good to know

The relay is compliant with international standards, ensuring compatibility and safety. Its screw terminals accept a range of conductor sizes, and the IP20 rating suits installation inside enclosures. Temperature compensation maintains trip accuracy across varying ambient conditions, making it a dependable choice for industrial automation.