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Our comprehensive selection of low-voltage electrical distribution products includes Miniature Circuit Breakers, contactors, distribution boards, and panel meters, ensuring safe and dependable solutions for your application requirements.


TOSUNlux circuit breaker will give you and your equipment the highest level of protection, ensure 100% absolute safety.

TOSUNlux TSB4-63 miniature circuit breaker  serves as a means of safeguarding lighting distribution system or motor distribution system against overloading and short-circuiting. This new product boasts a neoteric structure which is lightweight, reliable and excels in performance.

There are several reasons why this product stands out. Firstly, it has a high breaking capacity and trips quickly in case of overload or short-circuit. Additionally, it is designed using fire-resistant and shockproof plastics which make it highly durable. It is worth noting that our products have been certified by INTERTEK and BV, and fully comply with the IEC60898 standard.

TOSUNLux Miniature Circuit Breaker

TOSUNlux offers a full range of MCBs covering most applications and markets

Why Choose TOSUNlux Brand?

Multiple Product Lines

We are a company that offers a full range of safe and reliable low-voltage electrical distribution products and lighting products.

Quality and Certification

TOSUNlux’s power supply units are high-performance, reliable, and innovative, making them suitable for the most demanding industrial applications.

Main products from us have gained IEC type test report and approval issued by world famous laboratories, such as VDE, INTERTEK, BV, DEKRA and TUV.

More Safety

TOSUNlux low voltage products and systems fulfill users’ needs for power, safety, and convenience, providing constant proof of their reliability in residential and commercial buildings, industry, power plants, machinery, and equipment of all kinds on every continent.

30+ Years Experience

TOSUNlux is a trusted brand for power distribution because of our experience in providing innovative products and solutions for over 30 years.

Perfect dealer system

We understand the demands of the marketplace and work with distributors to achieve the highest quality customer service.


TOSUNlux ‘s Sevice experience helps simplify processes, reduce costs, and increase production, which can help customers run their operations faster, more safely, and at a lower cost.

About TOSUNlux

TOSUNlux is a Chinese manufacturer of electrical circuit breakers, including the TSB3-63 miniature circuit breaker (MCB) used for overload and short-circuit protection in lighting or motor distribution systems.

We offer a range of circuit breakers, including high breaking capacity 6kA MCBs and residual current circuit breakers.

Quality and Certification

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All Your Questions

Here are some frequently asked questions about TOSUNlux Miniature Circuit Breaker

The primary distinctions between a circuit breaker and a miniature circuit breaker (MCB) lie in their tripping mechanism, breaking capacity, and voltage rating. Circuit breakers utilize a tripping relay mechanism, whereas MCBs employ a tripping release mechanism. While circuit breakers possess a high rupturing capacity, MCBs have a low rupturing capacity. Furthermore, circuit breakers are suitable for high voltage systems, whereas MCBs are appropriate for low voltage systems. MCBs are specifically designed to shield electrical circuits from harm caused by overcurrent conditions.

When selecting the appropriate MCB for a specific application, it is crucial to take into account technical aspects such as voltage, frequency, and current rating. Ensure that the current rating of the MCB does not exceed the cable’s current carrying capacity. Additionally, choose the MCB type based on its intended use. For instance, Type C MCBs are optimal for domestic appliances with medium current loads, whereas Type D MCBs can handle higher current rates. Lastly, do not forget to consider the breaking capacity and the number of poles necessary for the application.

The main distinction between Type A and Type B MCBs lies in their sensitivity to overcurrent. Type A MCBs are engineered for low levels of overcurrent protection, primarily serving to safeguard highly sensitive devices. In contrast, Type B MCBs are widely employed to shield low-power domestic circuits and residential applications from overcurrent. As Type B MCBs are less sensitive compared to Type A MCBs, they can accommodate higher levels of overcurrent. The fundamental difference among Type B, C, or D devices hinges on their capacity to manage surge currents without being triggered.

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Miniature Circuit Breakers (MCBs) play a crucial role in ensuring the safety and efficient operation of various electrical devices. Commonly found in both industrial and domestic settings, MCBs are integrated into electrical appliances such as lights, heaters, and fans. They serve multiple purposes, including functioning as local control switches, isolating switches for fault protection, and providing overload protection for installations. MCBs are an effective replacement for rewirable switch-fuses in low-power domestic and industrial applications, offering three valuable functions in a single component.

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We Help Your Business to Connect and Grow on Large Scale

TOSUNlux has its own design team with a 5-people in-house design team, which provides 4-5 new series of products every year for our clients.

The Complete Guide to Miniature Circuit Breakers


Miniature Circuit Breakers (MCBs) are compact, reliable, and crucial safety devices used in electrical systems to prevent electrical hazards. Protecting various types of electrical loads, such as motors, transformers, and consumer appliances, MCBs play a critical role in any electrical setting. This comprehensive guide will discuss what MCBs are, their types, applications, and advantages to help you understand their importance in electrical safety.

What are Miniature Circuit Breakers (MCBs)?

Miniature Circuit Breakers (MCBs) are electromechanical devices designed to protect electrical circuits from overloads and short circuits. When a fault occurs, the MCB automatically trips, stopping the flow of current within the circuit. This prevents damage to electrical equipment, reduces the risk of fires, and safeguards against electrocution hazards. MCBs are commonly used in residential, commercial, and industrial installations.

Types of Miniature Circuit Breakers (MCBs)

Based on their tripping characteristics, MCBs are available in several types—Type B, Type C, and Type D.

1. Type B MCBs: These MCBs are designed to trip at a current between three and five times their rated current capacity. Suitable for light loads such as lighting circuits, domestic appliances, and outlets, Type B MCBs offer quick protection against short circuits.

2. Type C MCBs: With a tripping range between five and ten times their rated current, Type C MCBs protect against both short circuits and overloads. They are commonly used in commercial and industrial applications, including motors, lighting circuits, and transformers.

3. Type D MCBs: These MCBs can handle currents between ten and twenty times their rated capacity, making them suitable for heavy loads like large motors and industrial equipment. Type D MCBs provide immediate protection against short circuits, while allowing for brief overload tolerances before tripping.

Working Principle of MCBs

MCBs operate based on two major principles: thermal and magnetic tripping.

1. Thermal Tripping: The thermal tripping mechanism relies on a bimetallic strip that bends when heated due to current excess. The bending causes the trip mechanism to activate, separating the contacts and opening the circuit. This reaction is slower but provides precise protection against overloads.

2. Magnetic Tripping: Utilizing an electromagnetic coil, magnetic tripping activates when a fault (short circuit) causes a rapid increase in current. The magnetic field generated by the increased current forces the trip mechanism into motion, quicky disconnecting the circuit. This reaction is almost instantaneous, enabling fast-acting protection from short circuits.

Applications of Miniature Circuit Breakers (MCBs)

1. Residential: In homes, MCBs protect appliances and electrical devices from faults and overloads. They offer a safer alternative to traditional fuses, being both reusable and more reliable.

2. Commercial: MCBs are essential in commercial settings like offices and retail stores, safeguarding electrical systems against overloads, short circuits, and equipment malfunctions. They help prevent costly damages, ensuring the smooth operation of businesses.

3. Industrial: MCBs serve a critical role in the safe operation of industrial electrical systems, including protection of motors, transformers, and machinery. They help minimize downtime due to equipment failure, maximizing productivity.

Advantages of Miniature Circuit Breakers (MCBs)

1. Reliable Protection: MCBs provide superior protection compared to traditional fuses, instantly tripping during faults or overloads to minimize damages and hazards.

2. Compact Size: Miniature Circuit Breakers offer robust protection in a compact form factor, making them ideal for modern, space-saving electrical installations.

3. Easy Reset: After a fault has been resolved, MCBs can be easily reset by switching them back to the “ON” position, eliminating the need to replace fuses or components.

4. Visual Indication: MCBs feature an easily visible trip indicator, allowing users to confirm the tripped status at a glance and quickly identify the source of the issue.

5. Reduced Installation Time: With their easy installation process, MCBs can be mounted conveniently on DIN rails, reducing both installation time and effort.


TOSUNlux TSB3-63 miniature circuit breaker (MCBs) are essential and reliable components that improve electrical safety and circuit protection. With their compact size, ease of use, and enhanced performance across various applications, MCBs are a trusted solution for electrical systems maintenance and protection. By understanding the types, applications, and advantages of MCBs, users can confidently select and install appropriate protective devices for their specific electrical needs.

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