ABB TF42-10 Thermal Overload Relay, 8-10 A, Class 10, 690 V AC, 3-Pole, 1NO+1NC 1SAZ721201R1043

Engineered for reliable motor protection, the ABB TF42-10 thermal overload relay offers a precise current setting range of 8.00 to 10.00 A, ensuring accurate tripping under overload conditions. Its Class 10 trip characteristic provides fast response to protect motors from thermal damage, while the 3-pole design supports three-phase applications up to 690 V AC. With a rated insulation voltage of 690 V and impulse withstand of 6 kV, this relay is built for demanding industrial environments.

Overview

The TF42-10 is part of ABB's proven thermal overload relay family, designed for direct mounting on ABB contactors from AF09 to AF42 and A9 to A42. It features both manual and automatic reset modes, allowing flexibility in system design. The relay includes one normally open (NO) and one normally closed (NC) auxiliary contact for signaling and control, with screw terminals for secure connections. Phase failure sensitivity is integrated, providing additional protection against single-phasing conditions.

What stands out

• Wide current adjustment range from 8 to 10 A for precise motor matching.
• Class 10 trip curve ensures quick disconnection on overload, minimizing motor stress.
• Phase failure sensitivity detects unbalanced loads, preventing motor burnout.
• Dual reset modes (manual/automatic) adapt to various operational needs.
• Compact design with direct contactor mounting saves panel space and wiring time.

Technical details

• Current setting range: 8.00 - 10.00 A
• Trip class: Class 10
• Number of poles: 3
• Rated operational voltage (Ue): 690 V AC
• Rated insulation voltage (Ui): 690 V
• Rated impulse withstand voltage (Uimp): 6 kV
• Auxiliary contacts: 1 NO + 1 NC
• Main circuit connection: Screw terminals
• Auxiliary circuit connection: Screw terminals
• Mounting: Direct contactor mounting (AF09-AF42, A9-A42)
• Reset type: Manual and automatic
• Ambient operating temperature: -25 to +60 °C
• Ambient storage temperature: -40 to +70 °C
• Degree of protection: IP20
• Power loss: 7.5 W
• Phase failure sensitivity: Yes
• Standards: IEC/EN 60947-1, IEC/EN 60947-4-1, IEC/EN 60947-5-1

Our verdict

A robust and precise thermal overload relay that delivers dependable motor protection in compact form. Its combination of adjustable settings, phase failure detection, and easy contactor integration makes it a top choice for industrial motor control applications.