Abb tf42-1.7 Thermal Overload Relay 1.3 to 1.7 a

Product Description

The ABB tf42-1.7 is a thermal overload relay designed to provide electromechanical overcurrent protection in motor control circuits. It guards motors against damage caused by sustained overload conditions and phase failure, tripping within Class 10 response times to limit thermal stress on the motor windings. The relay features built-in temperature compensation, a trip-free mechanism that prevents bypass of the protective function, and a clearly visible trip indication. The adjustable current range spans 1.3 to 1.7 amps, making it suited for smaller motor loads. Licensed electricians and motor control technicians are the typical installers.

This relay is used in residential and light commercial motor control applications where compact, direct-mount overload protection is required. It mounts directly to compatible block contactors, simplifying panel assembly and reducing wiring complexity. The STOP function allows the relay to serve a dual role in the control circuit. Both automatic and manual reset modes are selectable, giving the installer flexibility based on the restart requirements of the application and local safety protocols.

Key Features

• Adjustable current range of 1.3 to 1.7 amps for precise motor protection
• Trip Class 10 response for fast protection against overload conditions
• Phase failure detection to prevent single-phasing damage to motors
• Temperature compensation maintains consistent trip accuracy across ambient conditions
• Trip contact (NC) and signal contact (NO) included for control circuit integration
• Selectable automatic or manual reset and trip-free mechanism prevent unsafe restart

Compatibility

Designed for direct mounting to compatible block contactors in motor control assemblies. Single mounting kits are available as an accessory for standalone installation configurations.

Installation Notes

Installation should be performed by a licensed electrician in accordance with the National Electrical Code (NEC) and applicable local codes. De-energize and lock out the circuit before installing or adjusting the relay. Verify the current adjustment dial is set to match the motor full-load amperage rating before energizing. Confirm reset mode selection matches the application restart requirements prior to commissioning.