Buy Quality Miniature Circuit Breaker from China

MCB stands for Miniature Circuit Breaker. It is the most widely used automatic protection device in building electrical terminal distribution. Other devices such as RCCB, RCBO, MCCB, and ACB are also configured in the distribution terminal. XENHO, as a professional MCB manufacturer, has extensive experience and has been an MCB factory in China for many years, offering free MCB samples.

Two types of trip units:

Thermal overload relay (bimetallic strip): Used for overload protection. When the current exceeds the rated value and persists for a certain period, the bimetallic strip heats up and bends, triggering a mechanism to disconnect the circuit.

Magnetic trip unit (electromagnetic coil): Used for short-circuit protection. When the current reaches an extremely high short-circuit value, the coil generates a strong magnetic force that instantly attracts the armature, triggering the mechanism to quickly disconnect the circuit (usually within milliseconds).

Rated Current (In)

The current at which the MCB (Miniature Circuit Breaker) can operate normally for an extended period. Common values include 6A, 10A, 16A, 20A, 25A, 32A, 40A, 50A, and 63A, with an upper limit typically of 125A. This amperage represents the maximum current that the circuit breaker can safely carry for a long time without overheating or tripping. Choosing the appropriate rated current is crucial for ensuring circuit safety and protecting electrical equipment.

6A: Lighting circuits, small socket circuits

10A: General socket circuits (e.g., bedrooms, living rooms), lighting circuits, general appliances such as computers and televisions.

16A: High-power dedicated sockets (e.g., wall-mounted air conditioners, electric water heaters, small kitchen appliances), larger lighting circuits.

20A/25A: Higher-power appliances such as cabinet air conditioners, instantaneous water heaters, and small electric heaters.

32A: Main circuit for areas with concentrated high-power appliances such as kitchens and bathrooms, or the main line for small shops.

40A/50A/63A: Main switch for household power entry, small three-phase motors, main switch for power distribution boxes, or main incoming lines for larger shops or offices.

Breaking capacity (Icu)

The maximum short-circuit current value that the durable MCB can safely interrupt, such as 4.5kA, 6kA, 10kA, etc. This value must be greater than the expected short-circuit current at the installation point; otherwise, it may lead to an accident.

Tripping characteristics (curve)

This shows the relationship between the tripping time of the MCB and the overload current multiple, and is crucial for selection. It is divided into types A, B, C, and D:

Type A: 2-3 times In, mainly used in semiconductor circuits and measurement circuits requiring fast protection.

Type B: 3-5 times In, mainly used in resistive loads, such as residential circuits, lighting, and electric heaters.

Type C: 5-10 times In, commonly used in general power distribution, such as fluorescent lamps, power distribution, and mixed circuits containing small power motors.

Type D: 10-20 times In, for high-impact loads, such as transformers, solenoid valves, and motors with large starting currents.

Among these four models, Type C is the most widely used, mainly in residential areas, and the demand is also the largest.

As a professional manufacturer and supplier specializing in MCB production in China, XENHO can provide you with cheap but durable circuit breakers. At the same time we support the service of customization, you can customize products that meet your requirements. Feel free to contact us!