ABB TNR 25590 TNR25590 Thermal Overload Relay

ABB TNR 25590 TNR25590 Thermal Overload Relay

Product Overview

ABB TNR 25590 (abbreviated as TNR25590) is a high-performance thermal overload relay designed specifically for overload protection of AC motors. As the core protection component in the motor control circuit, it can accurately monitor the working current of the motor. When overload, stall, or phase loss faults occur, causing abnormal current rise, it quickly cuts off the control circuit to protect the motor from overload damage. It is widely used in various industrial motor drive systems such as fans, pumps, compressors, and conveyors.

This product relies on ABB's profound technical accumulation in the field of low-voltage electrical appliances, using advanced bimetallic heating principles and precise mechanical tripping mechanisms. It has the characteristics of reliable action, flexible adjustment, and strong tolerance. It can be perfectly matched with ABB AC contactors to form a complete motor starting and protection solution, providing strong guarantees for the continuity and safety of industrial production.

Core Features

1. Precise overload protection with stable response characteristics

TNR25590 uses high-quality bimetallic strips as the core sensing element. When the motor current passes through the thermal element, the bimetallic strips bend and deform due to heat generation. The amount of deformation is proportional to the square of the current and the duration of electrification, which can accurately simulate the heating characteristics of the motor. The product has a wide range of current regulation capabilities, high precision in protecting current settings, stable operating characteristics, and can effectively distinguish between normal starting current and fault overload current, avoiding misoperation while ensuring rapid response in the event of a real fault.

2. Comprehensive fault protection, covering multiple risks

In addition to the basic overload protection function, this relay also has complete phase loss protection capability. When a phase disconnection fault occurs in the motor, the currents of the other two phases will sharply increase. TNR25590 can quickly identify this fault state through a special current induction structure and trigger protection actions to prevent winding burnout caused by phase loss operation of the motor. At the same time, for serious faults such as motor stalling, it has a short delay tripping characteristic, which can cut off the circuit in a short time and minimize equipment damage.

3. Flexible adjustment function, adaptable to various scenarios

The product supports flexible adjustment of parameters such as overload current and reset mode. The overload current regulation range covers a specific range (subject to actual specifications), and can be accurately matched according to the rated current of different power motors; The reset method provides two options: manual reset and automatic reset. Manual reset requires manual operation for recovery, which is suitable for scenarios where the cause of the fault needs to be clarified. Automatic reset can recover on its own after troubleshooting and cooling of the bimetallic strip, improving equipment operating efficiency and meeting the needs of different working conditions.

4. High mechanical strength and strong environmental adaptability

Adopting reinforced plastic shell and precision mechanical structure design, the shell has good impact resistance and wear resistance performance. The internal release mechanism has undergone tens of thousands of mechanical life tests, and the action is reliable and not easy to get stuck. The product can operate stably within an environmental temperature range of -20 ℃ to+60 ℃, with a relative humidity of ≤ 95% (no condensation), and can adapt to complex industrial environments in multiple industries such as metallurgy, chemical engineering, and building materials. The protection level reaches IP20, effectively isolating external dust and foreign object interference.

5. Convenient installation and maintenance to improve work efficiency

Supports two installation methods: standard DIN rail installation and bolt fixed installation. It can be flexibly selected according to the layout of the control cabinet and matched with the installation size of ABB series contactors, making it easy to assemble in sets. The product is equipped with clear current regulation scales and status indicator windows, which intuitively display the set current value and relay working status (such as normal and tripped), making daily inspections and parameter adjustments convenient; The terminal block adopts a crimping design, which ensures firm wiring, low contact resistance, and reduces the risk of heat generation.

Technical parameters

model

TNR 25590（TNR25590）

protection function

Overload protection, phase loss protection, and locked rotor protection

Rated insulation voltage (Ui)

690V AC

Rated working voltage (Ue)

400V AC (regular application), 690V AC (specific scenario)

Set current range

According to specific sub models, the typical range is 10A-16A (subject to official parameters)

Rated working current (Ie)

Match with the upper limit of the set current, with a typical value of 16A (based on official parameters)

Release level

Class 10 (regular model), other grades can be selected according to requirements

Reset method

Manual reset/automatic reset (switchable)

reset time

Manual reset: immediate; Automatic reset: typical 30s to 60s (after cooling)

Installation method

35mm standard DIN rail installation, bolt fixed installation

Protection level

IP20

Working environment temperature

-20℃~+60℃

contact form 

1 normally closed (NC), auxiliary contact capacity AC 230V/5A

Applicable scenarios

-General industrial motor protection: suitable for motors of general mechanical equipment such as fans, water pumps, oil pumps, etc., to prevent motor damage caused by overload and phase loss, such as sewage pumps in sewage treatment plants and workshop ventilation fans.

-Compressor and refrigeration equipment: used for protecting air conditioning compressors and cold storage refrigeration compressors, avoiding overload faults caused by excessive load or refrigerant leakage, and ensuring stable operation of the refrigeration system.

-Conveyor and transmission equipment: In transmission equipment such as belt conveyors, chain conveyors, and machine tool spindles, the electric motor is protected from overload impact caused by faults such as stalling and jamming, ensuring continuous operation of the production line.

-Building and HVAC equipment: Used for motor protection of fan coil units, cooling tower fans, heating circulation pumps, and other equipment in building air conditioning systems to enhance the reliability of building electromechanical systems.

-Metallurgical and chemical industries: In the control circuits of electric motors such as conveyor rollers in the metallurgical industry and mixing equipment in the chemical industry, they resist current fluctuations in complex environments and achieve stable protection.

Installation and usage precautions

1. Installation points

-Before installation, it is necessary to confirm that the product model matches the motor parameters to ensure that the set current adjustment range covers the rated current of the motor, in order to avoid protection failure or misoperation.

-The installation location should avoid direct sunlight, high-temperature heat sources (such as heaters, high-power resistors), and strong vibration areas. The ambient temperature should be within the allowable range of the product to prevent affecting the induction accuracy of the bimetallic strip.

-When wiring, it is necessary to strictly distinguish between the main circuit terminals and the control circuit terminals. The main circuit should be connected to the motor power circuit, and the control circuit should be connected to the contactor coil circuit. The wiring should be firm to avoid heating or protection delay caused by poor contact.

-When installed together with the contactor, it should be ensured that the distance between the two is not less than 5mm, and sufficient heat dissipation space should be reserved to prevent the contactor from overheating and transmitting to the relay, which will affect its performance.

2. Precautions for use

-Before putting into use, it is necessary to accurately adjust the setting current value of the relay according to the rated current of the motor. When adjusting, reference should be made to the product scale, and if necessary, the protection characteristics should be verified through actual load testing.

-After the relay is activated, the cause of the fault (such as overload, phase loss, mechanical jamming, etc.) should be investigated first. After the fault is eliminated, the reset operation should be carried out. It is forbidden to reset repeatedly without identifying the cause.

-During daily maintenance, it is necessary to regularly check whether the wiring terminals are loose, whether the housing is damaged, remove dust and debris at the terminals, ensure good contact between the contacts, and conduct an annual action characteristic test to verify the protective performance.

-It is prohibited to disassemble the casing or adjust the internal structure while the relay is energized. During maintenance, the power supply of the main circuit and control circuit must be cut off first to prevent electric shock or equipment damage.

-When the motor starts frequently (such as frequent forward and reverse rotation), the impact of starting current on the relay should be considered, and if necessary, a model with corresponding tolerance should be selected to avoid fatigue damage to the relay.