The thermal overload relay serves as a crucial protective device in electrical systems, primarily used to safeguard motors from overheating and potential damage due to excessive current. It operates based on the principle of thermal sensing, monitoring the heat generated by the motor during operation. In industrial and civil electrical systems, motors are core power components, and long-term overload, phase failure or abnormal current will cause the motor to overheat, which may burn out the motor windings, damage equipment and even cause safety accidents. As a dedicated motor protection device, the thermal relay can timely cut off the control circuit when the motor is overloaded, stop the motor operation, and effectively avoid motor damage. Zhejiang C&J Electrical co., ltd. (referred to as C&J Electrical) focuses on high-quality electrical protection devices, and its LR2 seriesthermal relay integrates multiple protection functions, excellent performance and convenient use, providing reliable protection for various AC motors.
Thermal Relay & LR2 Series: Core Overview
To fully understand the thermal relay, it is necessary to first clarify its working principle and core positioning. A thermal relay is an electrical protection device that uses the thermal effect of current to realize overload protection. Its internal core component is a thermal element (usually a bimetallic strip), which is connected in series in the motor power circuit. When the motor operates normally, the current passing through the thermal element is within the rated range, and the heat generated is not enough to make the bimetallic strip deform; when the motor is overloaded or phase-failed, the current increases significantly, the heat generated by the thermal element accumulates rapidly, the bimetallic strip deforms due to thermal expansion and contraction, and drives the contact mechanism to act, cutting off the motor control circuit, so as to achieve the purpose of protecting the motor.
C&J Electrical’s LR2 series thermal relay is a high-performance product designed for AC motor protection, which fully complies with international and national standards and is widely used in various AC circuits. The LR2 series thermal overload relays (hereinafter referred to as thermal relays) are mainly used in AC 50, 60Hz, rated operating voltage Ue: 380V, rated current 0.10~93 (A) circuits for overload, phase failure and protection of circuits and motors. Compared with ordinary thermal relays, the LR2 series has more comprehensive functions, more reliable performance and more flexible installation, which can fully meet the protection needs of different types of AC motors in various scenarios.
Core Functions of LR2 Series Thermal Relay
As a professional motor protection device, the LR2 series thermal relay of C&J Electrical undertakes multiple core protection functions, which are directly related to the safe and stable operation of the motor. Its functional characteristics are comprehensive and practical, mainly including the following aspects:
- Overload protection function: This is the most basic and core function of the thermal relay. When the motor is overloaded, the current exceeds the rated value, and the thermal element of the LR2 series thermal relay will generate heat and deform, triggering the contact to disconnect, cutting off the control circuit, and stopping the motor to avoid overheating damage. It can be adapted to different overload conditions by adjusting the setting current.
- Phase failure protection function: Phase failure is one of the main causes of motor burnout. The LR2 series thermal relay is equipped with a phase failure protection function, which can quickly detect the phase failure fault of the motor power supply, and timely cut off the circuit to protect the motor from damage caused by phase failure operation.
- Temperature compensation function: The operation of the thermal relay is easily affected by the ambient temperature. The LR2 series is designed with a temperature compensation function, which can automatically compensate for the influence of ambient temperature changes, ensuring that the action accuracy of the thermal relay is not affected by the ambient temperature, and improving the reliability of protection.
- Flexible reset mode: It supports optional automatic reset and manual reset. Users can choose the appropriate reset mode according to the actual application scenario, which is more flexible and convenient to use. Automatic reset is suitable for scenarios that need to resume operation quickly after fault elimination, and manual reset is suitable for scenarios that need manual confirmation before resuming operation.
- Action indication and auxiliary contact function: It is equipped with an action indication signal, which can clearly display whether the thermal relay is in the action state, facilitating fault inspection and maintenance. At the same time, it is equipped with moving and closing auxiliary contacts with insulation separation, which can be connected to the control circuit to realize interlocking control and signal transmission.
- Safe and reliable design: It is equipped with a test button and a stop button, which can be used to check the flexibility of the thermal relay action, ensuring that the product can work normally when a fault occurs. The guard is designed to prevent finger electric shock, and the locking device prevents misoperation, ensuring safe use.
Application Scenarios of LR2 Series Thermal Relay
Due to its comprehensive protection functions, reliable performance and wide adaptability, the LR2 series thermal relay of C&J Electrical is widely used in various AC motor protection scenarios, covering industrial production, civil electrical, commercial and other fields. The main application scenarios are as follows:
- Industrial production field: It is widely used in the protection of various motors in factories, workshops and other places, such as water pump motors, fan motors, conveyor motors, compressor motors, etc. It can effectively protect the motors from overload, phase failure and other faults, ensuring the normal operation of the production line.
- Civil electrical field: It is used in the protection of motors in household electrical equipment and civil facilities, such as air conditioner compressors, water heaters, exhaust fans, water pumps for domestic water supply, etc., avoiding motor damage caused by overload or phase failure, and ensuring the normal use of household electrical equipment.
- Commercial field: It is applied to the protection of motors in commercial facilities, such as central air conditioning systems, ventilation systems, escalators, elevators, refrigeration equipment, etc., ensuring the safe and stable operation of commercial facilities and avoiding economic losses caused by motor faults.
- Other fields: It is also used in the protection of motors in special environments, such as construction machinery motors, agricultural machinery motors, etc. The small installation area and various installation methods of the LR2 series make it suitable for various complex installation environments.
C&J Electrical LR2 Series Thermal Relay: Core Advantages & Technical Parameters
As a core product of C&J Electrical in the field of thermal relay, the LR2 series has obvious competitive advantages in terms of performance, safety and usability. Its core advantages and detailed technical parameters are as follows:
Core Product Advantages
- Comprehensive protection functions: Integrates overload protection, phase failure protection, temperature compensation and other functions, which can comprehensively protect the motor from various faults and improve the reliability of the motor operation.
- High compliance and reliability: Complies with IEC60947-4/GB14048.4 international and national standards, strictly controls product quality during production, and has stable and reliable performance, which can meet the use requirements of various harsh environments.
- Flexible and convenient to use: Supports setting current adjustment, optional automatic reset and manual reset, with action indication signal, which is convenient for users to operate, adjust and maintain; the test button and stop button are designed to facilitate the inspection of product performance.
- Safe design: Equipped with a guard to prevent finger electric shock and a locking device to prevent misoperation, which ensures the safety of users during operation and use; the insulation separation of auxiliary contacts further improves the safety performance.
- Space-saving and flexible installation: Small installation area, various installation methods, can be installed according to different application scenarios and equipment layouts, which is convenient for integration into various electrical control cabinets.
- Good environmental adaptability: With damp heat protection treatment, it can adapt to humid and hot working environments, and the temperature compensation function ensures that the product can work stably in different ambient temperatures.
- Customizable services: C&J Electrical supports OEM/ODM brand customization services for the LR2 series thermal relay, with multiple specifications available, which can meet the personalized needs of different customers and markets.
Detailed Technical Parameters
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Parameter
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Details
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|---|---|
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Compliance Standard
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IEC60947-4/GB14048.4
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Protection Level
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IP20
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Protective Treatment
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Damp heat
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Wiring Specification
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c.s.a 1/2.5
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Flexible Cable Wireless Terminal
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1/2.5
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Tightening Torque
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1.2
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Rated Operating Voltage (Ue)
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380V
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Rated Current Range
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0.10~93 (A)
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Applicable Frequency
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AC 50Hz, 60Hz
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Reset Mode
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Automatic reset and manual reset (optional)
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Auxiliary Contact
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Moving and closing auxiliary contacts (insulation separation)
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Why Choose C&J Electrical LR2 Series Thermal Relay?
In the field of thermal relay, there are many products on the market, but C&J Electrical’s LR2 series stands out with its comprehensive advantages and becomes the preferred choice for customers pursuing safety, reliability and flexibility. The reasons for choosing it are as follows:
- Professional motor protection: Focus on AC motor protection, integrate multiple protection functions, accurately respond to overload, phase failure and other faults, and effectively extend the service life of the motor, reducing the cost of equipment maintenance and replacement.
- High quality and compliance: Strictly comply with international and national standards, adopt high-quality materials and advanced production technology, and pass strict quality inspection, ensuring that the product has stable performance and long service life.
- Humanized design: Combined with the actual use needs of users, the design of setting current adjustment, optional reset mode, action indication and other functions makes the product more flexible and convenient to use, reducing the difficulty of operation and maintenance.
- Strong adaptability: Small installation area, various installation methods, damp heat protection treatment and temperature compensation function, which can adapt to various complex working environments and meet the protection needs of different types of motors.
- Safe and reliable: Multiple safety protection designs, such as anti-electric shock guard and anti-misoperation locking device, ensure the safety of users and equipment, and avoid safety accidents caused by product failure.
- Flexible customization services: Support OEM/ODM brand customization and multiple specifications to choose from, which can be tailored to the personalized needs of different customers and markets, enhancing the competitiveness of customers’ products.
- Professional after-sales support: C&J Electrical has a professional technical and after-sales team, which can provide customers with product selection guidance, technical consultation and after-sales maintenance services, solving customers’ worries about use and maintenance.
Get in Touch
If you have any questions about the LR2 seriesthermal relay, such as product specifications, technical details, customization needs, or bulk orders, please feel free to contact C&J Electrical. Our professional team will provide you with high-quality electrical protection solutions and reliable services, ensuring the safe and stable operation of your motor and electrical system.
Post time: Feb-03-2026