How to Choose MCB for Home: A Comprehensive Guide

In modern home electrical systems, Miniature Circuit Breakers (MCBs) are essential devices for ensuring electrical safety. Choosing the right MCB not only protects electrical equipment from overload and short circuit damage but also prevents fire hazards caused by electrical faults. However, faced with the variety of MCB products on the market, many homeowners often feel confused: What specifications of MCB should I choose? What are the differences between different types of MCBs? How do I select the most suitable MCB based on my home’s electrical needs?

This article provides a comprehensive guide to choosing MCBs for home use, covering everything from basic concepts and working principles to selection methods and installation maintenance. It will help you easily master the professional knowledge needed to choose appropriate MCBs, ensuring safe and reliable home electricity use. Whether you’re preparing to renovate a new house, replace old circuit breakers, or simply want to learn about home electrical safety, this guide will provide practical reference information.

I. Definition and Basic Functions of MCBs

A Miniature Circuit Breaker (MCB) is an automatic electrical switch designed to protect circuits from damage caused by overload current and short circuits. Unlike traditional fuses, MCBs can be reset after a fault is cleared, without needing replacement.

1.1 Main Functions of MCBs

MCBs serve multiple protective functions in home electrical systems:

• Overload Protection: When current in a circuit exceeds the safe limit but hasn’t reached short circuit levels, the MCB disconnects the circuit after a certain delay, preventing wire overheating and insulation damage.
• Short Circuit Protection: When a short circuit occurs, the MCB quickly disconnects the circuit within milliseconds, preventing damage from high currents.
• Isolation Function: MCBs can be manually operated as isolation switches, facilitating maintenance and inspection of electrical equipment.
• Fault Indication: Many modern MCBs are equipped with status indicators that show whether the breaker has tripped due to overload, short circuit, or manual operation.

1.2 Basic Structure of MCBs

A typical MCB consists of the following parts:

• Operating Mechanism: The switch handle used to manually connect or disconnect the circuit.
• Contact System: Including fixed and moving contacts, used to connect or disconnect the circuit.
• Arc Extinguishing Device: Used to quickly extinguish arcs produced when the circuit is disconnected.
• Thermal-Magnetic Trip Unit: Including a thermal trip unit (for overload protection) and a magnetic trip unit (for short circuit protection).
• Terminals: Connection terminals for external wires.

II. Differences and Advantages of MCBs Compared to Traditional Fuses

Before learning how to choose MCBs, it’s important to understand the advantages of MCBs compared to traditional fuses, which helps explain why modern home electrical systems generally use MCBs rather than fuses.

2.1 Main Differences Between MCBs and Fuses

2.2 Advantages of MCBs

MCBs have the following significant advantages compared to traditional fuses:

• Higher Safety: MCBs have more stable operating characteristics and more reliable protection, reducing safety hazards caused by protection device failure.
• Longer Service Life: MCBs can withstand thousands of mechanical operations and dozens of electrical trips, far exceeding the lifespan of fuses.
• Lower Maintenance Cost: No need for frequent replacement, reducing maintenance costs and spare parts inventory.
• Safer Operation: The operating mechanism of MCBs is designed so that users don’t need to directly contact live parts, reducing the risk of electric shock.
• Strong Adaptability: Modern MCBs come in various specifications and types, allowing selection of appropriate products based on different application scenarios.

Note: Although MCBs have replaced traditional fuses in most home applications, fuses still have their unique advantages in certain special application scenarios (such as protection of equipment with special starting current requirements).

III. Working Principles and Application Scenarios of MCBs

3.1 Working Principles of MCBs

The working principle of MCBs is mainly based on two protection mechanisms: thermal tripping (thermal-magnetic) and magnetic tripping (electromagnetic).

• Thermal Tripping Mechanism: Used for overload protection. When current exceeds the rated value but hasn’t reached short circuit levels, the current flowing through the bimetallic strip generates heat, causing it to bend and deform, which triggers the tripping mechanism to disconnect the circuit. This mechanism has a delay characteristic – the higher the current, the shorter the action time.
• Magnetic Tripping Mechanism: Used for short circuit protection. When a short circuit occurs in the circuit, the large current produces a strong magnetic field, attracting the armature of the electromagnet, immediately triggering the tripping mechanism to disconnect the circuit. This mechanism responds extremely quickly, usually completing within milliseconds.

3.2 Main Application Scenarios of MCBs

In home environments, MCBs are mainly applied in the following scenarios:

• Main Incoming Line Protection: Installed after the electric meter at the main incoming line, serving as the main protection for the entire home circuit.
• Branch Circuit Protection: Protecting different circuits in the home, such as lighting circuits, socket circuits, air conditioning circuits, etc.
• Important Equipment Protection: Providing dedicated protection for high-power or important equipment, such as electric water heaters, electric ovens, washing machines, etc.
• Special Circuit Protection: Such as circuits in wet areas like bathrooms and kitchens, which usually need to be used in conjunction with residual current devices.

Tip: When choosing MCBs, different parameter requirements should be considered based on the specific application scenario. For example, kitchen appliances usually require MCBs with higher rated currents, while lighting circuits can use MCBs with smaller rated currents.

IV. Key Parameters of MCBs Explained

To choose the right MCB, you first need to understand the key parameters of MCBs and their meanings. Here are the most important parameters for home MCBs:

4.1 Rated Current (In)

Rated current is the maximum current that an MCB can carry for a long time without tripping. It is usually marked on the front panel of the MCB and is the most basic parameter when choosing an MCB.

Common rated current specifications for home MCBs include: 6A, 10A, 16A, 20A, 25A, 32A, 40A, 50A, 63A, etc. When selecting, the actual load current of the circuit should be determined. The general principle is that the rated current of the MCB should be greater than or equal to the design load current of the circuit, but should not be too large.

Calculation Tip: For general home circuits, the load current can be calculated using the formula I = P/U, where I is the current (amperes), P is the power (watts), and U is the voltage (volts). For example, a 2000W appliance at 220V voltage has a current of about 9.1A, so a 10A MCB can be selected.

4.2 Tripping Curve Type (B, C, D Type)

The tripping curve type determines the response characteristics of the MCB to short circuit current, mainly divided into three types: B, C, and D.

• Type B: Magnetic tripping current is 3-5 times the rated current. Suitable for pure resistive loads or circuits with very small inductive loads, such as home lighting circuits, ordinary socket circuits, etc.
• Type C: Magnetic tripping current is 5-10 times the rated current. Suitable for circuits with certain inductive loads or larger starting currents, such as household appliances, small motors, etc. This is the most commonly used type in homes.
• Type D: Magnetic tripping current is 10-20 times the rated current. Suitable for equipment with very large starting currents, such as large motors, transformers, etc. Less commonly used in home environments.

4.3 Breaking Capacity (Icu)

Breaking capacity is the maximum short circuit current that an MCB can safely break, usually measured in kiloamperes (kA). The breaking capacity of home MCBs is generally between 4.5kA and 10kA.

When selecting, ensure that the breaking capacity of the MCB is greater than the maximum possible short circuit current. For ordinary homes, a breaking capacity of 6kA is usually sufficient, but for residences with larger power capacity or closer to substations, MCBs with higher breaking capacity may be needed.

4.4 Number of Poles (P)

The number of poles refers to the number of independent circuits that an MCB can control. Common types include 1P (single pole), 1P+N (single pole with neutral), 2P (double pole), 3P (three pole), and 4P (four pole).

• 1P (Single Pole): Only breaks the phase line, suitable for general lighting and low-power equipment circuits.
• 1P+N (Single Pole with Neutral): Breaks both the phase line and neutral line, providing better isolation effect.
• 2P (Double Pole): Simultaneously breaks the phase line and neutral line, suitable for circuits requiring higher safety, such as bathroom circuits.
• 3P (Three Pole): Used for three-phase circuits, such as three-phase motors.
• 4P (Four Pole): Used for three-phase four-wire systems, simultaneously breaking three phases and the neutral line.

For ordinary home single-phase power supply systems, 1P, 1P+N, and 2P type MCBs are mainly used.

4.5 Voltage Rating (Ue)

Voltage rating is the voltage range for which the MCB is designed to work. Home MCBs are usually 230V/400V (single-phase/three-phase), suitable for 220V/380V power grids. When selecting, ensure that the rated voltage of the MCB is not lower than the actual voltage used.

Warning: Using an MCB with a rated voltage lower than the actual grid voltage may result in equipment damage or safety hazards.

V. How to Choose the Right MCB for Your Home

Choosing the right MCB requires consideration of multiple factors. Here is a systematic selection method:

5.1 Determine the Circuit Type and Purpose

First, you need to clarify what type of circuit the MCB will be used for:

• Main Incoming Line: The main MCB protecting the entire home circuit
• Lighting Circuit: Branch circuit specifically for lighting equipment
• Socket Circuit: Socket branch circuit for connecting various household appliances
• Dedicated Circuit: Dedicated circuit set up for specific high-power equipment, such as air conditioners, electric water heaters, etc.

5.2 Calculate the Load Current

Calculate the required current based on the actual load of the circuit:

• Lighting Circuit: Calculate the total power of all lights, then divide by the voltage (220V) to get the current
• Socket Circuit: Consider the total power of appliances that may be used simultaneously, then divide by the voltage to get the current
• Dedicated Appliances: Directly check the rated current or power on the appliance nameplate
• Main Incoming Line: Consider the maximum possible electrical load of the home, usually determined based on the capacity approved by the power supply department

5.3 Choose the Rated Current

Choose the appropriate MCB rated current based on the calculated load current:

• The rated current of the MCB should be greater than or equal to the calculated load current
• Also consider the current-carrying capacity of the wire; the rated current of the MCB should not exceed the safe current-carrying capacity of the wire
• For equipment with starting current (such as motors, air conditioner compressors), consider the impact of the starting current

Recommended MCB rated current values for common home circuits:

5.4 Choose the Tripping Curve Type

Choose the appropriate tripping curve type based on the load characteristics of the circuit:

• Type B: Suitable for pure resistive loads, such as lighting circuits, electric heaters, etc.
• Type C: Suitable for most household appliance circuits, including those with small motors
• Type D: Suitable for equipment with particularly large starting currents, such as large air conditioners, elevators, etc.

For ordinary homes, Type C MCBs can meet the needs of most circuits.

5.5 Choose the Number of Poles

Choose the appropriate number of poles based on the connection method and safety requirements of the circuit:

• General lighting and socket circuits can use 1P (single pole) MCBs
• Circuits with higher safety requirements (such as bathroom circuits) are recommended to use 1P+N or 2P MCBs
• Three-phase equipment requires 3P or 4P MCBs

5.6 Choose the Breaking Capacity

Choose the appropriate breaking capacity based on the maximum possible short circuit current:

• A breaking capacity of 6kA is usually sufficient for ordinary residences
• Large residences or places with larger power capacity may require 10kA or higher

5.7 MCB Selection Flowchart

The following flowchart summarizes the steps for selecting home MCBs:

VI. Installation and Maintenance of Home MCBs

6.1 MCB Installation Location and Method

Correct installation of MCBs is crucial for ensuring their normal operation:

• Installation Location: MCBs should be installed in a dry, ventilated environment free from corrosive gases, avoiding direct sunlight and rain.
• Installation Method: MCBs are usually installed on standard DIN rails, fixed inside distribution boxes.
• Installation Direction: MCBs should be installed vertically, with the operating handle in the “ON” position when up and “OFF” position when down.
• Wiring Requirements: The incoming terminal (usually marked as “1”, “3”, “5”) connects to the power source side, and the outgoing terminal (usually marked as “2”, “4”, “6”) connects to the load side.

Safety Tip: MCB installation should be carried out by professional electricians. Non-professionals should not attempt to install or replace MCBs themselves to avoid electric shock or fire hazards.

6.2 Routine Maintenance and Inspection of MCBs

Regular maintenance and inspection of MCBs can extend their service life and ensure reliability:

• Regular Inspection: Check the appearance and working status of MCBs every 3-6 months to ensure there is no abnormal heating, odor, or noise.
• Test Operation: Manually operate the MCB switch a few times every 6-12 months to ensure the mechanical parts are flexible and reliable.
• Cleaning Maintenance: Keep the MCB surface clean; it can be gently wiped with a dry cloth. Never use a wet cloth or chemical cleaners.
• Load Check: Regularly check the load condition of the MCB to avoid long-term overload operation.

6.3 When to Replace MCBs

The following situations indicate that an MCB may need to be replaced:

• The MCB frequently trips without cause
• The MCB casing shows deformation, cracks, or scorch marks
• The operating handle is loose or cannot be reset normally
• The MCB has been used for over 15-20 years
• The home electrical load has increased, and the existing MCB specifications are no longer suitable

VII. Common Misconceptions in MCB Selection

When choosing home MCBs, people often fall into some misconceptions, which may lead to insufficient protection or over-protection:

7.1 Blindly Choosing Large Current MCBs

Some users believe that choosing MCBs with larger rated currents is better, as they won’t trip frequently. In reality, MCBs with excessively large rated currents will cause overload protection to fail, unable to cut off fault currents in time, increasing the risk of wire overheating and fire.

Correct Approach: The rated current of MCBs should be reasonably selected based on the actual load current and wire current-carrying capacity. It should neither be too small, causing tripping during normal use, nor too large, causing protection failure.

7.2 Ignoring Tripping Curve Type

Many users only focus on rated current when choosing MCBs, ignoring the selection of tripping curve type. Different types of loads require different tripping curve characteristics. Inappropriate selection may lead to false tripping during normal startup or untimely protection during short circuits.

Correct Approach: Choose the appropriate tripping curve type based on load characteristics. Generally, Type C MCBs are selected for household appliances, Type B for pure resistive loads, and Type D may be needed for large equipment.

7.3 Ignoring Breaking Capacity Parameter

Breaking capacity is the maximum short circuit current that an MCB can safely break. Choosing an MCB with insufficient breaking capacity may not safely break the circuit in case of a large current short circuit, potentially damaging the MCB or causing a fire.

Correct Approach: Choose an MCB with appropriate breaking capacity based on the power capacity and possible short circuit current level. Ordinary homes generally choose products with 6kA or above.

7.4 Ignoring Wire and MCB Matching

The matching of MCBs and wires is also an important consideration. If the current-carrying capacity of the wire is less than the rated current of the MCB, in an overload situation, the wire may overheat while the MCB won’t trip, creating a safety hazard.

Correct Approach: Ensure that the current-carrying capacity of the wire is not less than the rated current of the MCB, or choose an appropriate MCB based on the current-carrying capacity of the existing wire.

VIII. Brand and Quality Considerations for MCBs

The brand and quality of MCBs directly relate to home electrical safety. When selecting, pay attention to the following points:

8.1 Choose Well-Known Brands

MCBs from well-known brands usually have stricter quality control and more reliable performance. International brands such as ABB, Schneider, Siemens, etc., and domestic brands such as Chint, Delixi, Leaxin, etc., all have good market reputations.

8.2 Check Certification Marks

Qualified MCBs should have relevant certification marks, such as China’s CCC certification, Europe’s CE certification, etc. When purchasing, check whether the product has these certification marks and verify their authenticity through the certification body’s official website.

8.3 Pay Attention to Product Parameter Markings

Regular MCB products should clearly mark key parameters on the casing, including rated current, tripping curve type, breaking capacity, rated voltage, etc. Products with unclear markings or incomplete parameters should be purchased with caution.

8.4 Consider Cost-Effectiveness

MCB prices vary greatly, from tens to hundreds of dollars. When selecting, choose appropriate products based on the actual needs and budget of the home, ensuring basic safety performance. There’s no need to blindly pursue the highest-end products.

Recommendation: For ordinary home electricity use, choosing mid-priced products from well-known brands usually meets the needs; for important circuits or protection of high-value equipment, consider choosing high-end products.

IX. Case Analysis: MCB Selection for Different Home Scenarios

Through specific cases, we can more intuitively understand the MCB selection methods for different home scenarios.

9.1 Small Apartment (50-70 square meters)

Scenario Description: A small apartment with 1 bedroom, 1 living room, 1 kitchen, and 1 bathroom. Main appliances include: lighting, TV, computer, refrigerator, washing machine, air conditioner, electric water heater, etc.

MCB Configuration Recommendations:

9.2 Medium-Sized Home (90-120 square meters)

Scenario Description: A three-bedroom residence with 3 bedrooms, 1 living room, 1 kitchen, 2 bathrooms. Main appliances include: lighting, TV, computer, refrigerator, washing machine, dryer, multiple air conditioners, electric water heater, kitchen appliances, etc.

MCB Configuration Recommendations:

9.3 Large Home (150 square meters and above)

Scenario Description: A large residence with 4 bedrooms, 1 living room, 1 study, 1 kitchen, 3 bathrooms. Main appliances include: lighting, multiple TVs, computers, refrigerator, washing machine, dryer, multiple air conditioners, electric water heater, kitchen appliances, home theater, etc.

MCB Configuration Recommendations:

Note: The above cases are for reference only. Actual selection should be adjusted based on the specific electrical equipment and habits of each home. When performing electrical installation or renovation, it is recommended to consult professional electricians or engineers.

X. Combined Use of MCBs with Other Protective Devices

In home electrical systems, MCBs usually need to be used in combination with other protective devices to provide comprehensive electrical safety protection.

10.1 MCBs and Residual Current Devices (RCCB/RCBO)

Residual current devices are devices that detect leakage current in circuits and disconnect the circuit in dangerous situations, mainly used to prevent electric shock accidents.

• RCCB (Residual Current Circuit Breaker): Only provides leakage protection, does not have overload and short circuit protection functions, needs to be used in conjunction with MCBs.
• RCBO (Residual Current Circuit Breaker with Overcurrent Protection): Integrates the functions of MCB and RCCB, providing overload, short circuit, and leakage protection simultaneously.

Recommendations for Combined Use:

• Residual current protection devices should be configured for circuits in wet areas such as bathrooms and kitchens
• A large capacity RCCB (usually 30mA/40A or 63A) can be installed at the main incoming line, followed by MCBs for each branch circuit
• Or RCBOs can be configured separately for important circuits (such as bathrooms, kitchens), with ordinary MCBs used for other circuits

10.2 MCBs and Surge Protective Devices (SPD)

Surge protective devices are used to prevent damage to electrical equipment from lightning strikes or power grid surges.

Recommendations for Combined Use:

• Install SPD at the main incoming line to protect the entire home circuit
• For valuable or sensitive equipment (such as computers, home theater systems), add secondary SPD protection at their power sockets
• SPD should be used in conjunction with appropriately specified MCBs to disconnect the circuit promptly in case of SPD failure

10.3 MCBs and Electric Energy Meters

Modern homes increasingly install smart electric energy meters to monitor electricity consumption and usage patterns.

Recommendations for Combined Use:

• Electric energy meters are usually installed before MCBs, i.e., the power supply line first passes through the electric energy meter, then connects to the main MCB
• Sub-meters can be installed for different areas or important equipment, working with corresponding MCBs to achieve fine-grained electricity management

Comprehensive Protection Solution: A complete home electrical protection system typically includes: main incoming line MCB (or RCCB+MCB combination with main leakage protection), branch circuit MCBs, RCBOs for important areas, SPD, etc., forming a multi-level protection system.

XI. Frequently Asked Questions (FAQ)

What is the difference between MCB and air switch?

MCB (Miniature Circuit Breaker) and “air switch” are often confused in daily use. In fact, “air switch” is a colloquial term for MCB. Strictly speaking, a true air switch (ACB, Air Circuit Breaker) is a circuit breaker used for large current applications, with a relatively large size and rated currents typically above 630A. The so-called “air switches” used in homes are actually MCBs, which are miniaturized circuit breakers with rated currents typically between 1-125A.

Why does my MCB trip for no apparent reason?

MCBs tripping “for no apparent reason” usually have the following causes:

1. Actual load exceeds MCB rated current: Using multiple high-power appliances simultaneously causes current to exceed the MCB’s rated value
2. Short circuit fault in the circuit: Such as damaged wire insulation causing contact between phase and neutral lines
3. MCB aging or failure: After long-term use, the mechanical or thermal-magnetic elements of the MCB may degrade
4. Power grid voltage fluctuation: Sudden increase in grid voltage may cause current to increase
5. Excessive ambient temperature: High temperature environments will lower the MCB’s overload current threshold

Solutions: Check circuit load, investigate short circuit faults, replace aging MCBs, install voltage stabilizers, etc.

Can multiple MCBs be installed in one circuit?

Technically, multiple MCBs can be installed in series in one circuit, but this is usually not recommended because:

1. Multiple MCBs in series will cause protection coordination problems, making it difficult to determine which MCB will trip first
2. It increases system complexity and potential fault points
3. It increases circuit impedance, potentially causing larger voltage drops

The correct approach is: Use one appropriately specified MCB to protect one circuit, or use a main-branch distribution system, i.e., one main MCB with multiple branch circuits, each with its own MCB.

How long is the service life of an MCB?

The service life of an MCB depends on multiple factors:

1. Mechanical Life: Usually 10,000-20,000 operations
2. Electrical Life: Usually 8,000-10,000 make-break operations under rated load
3. Actual Service Years: Under normal home use conditions, quality MCBs can last 15-20 years

Factors affecting MCB life include: frequency of use, load conditions, ambient temperature, humidity, dust, etc. It is recommended to regularly check the working status of MCBs. If abnormalities are found (such as inflexible operation, deformed or discolored casing, etc.), they should be replaced promptly.

Can MCBs replace fuses?

In most home application scenarios, MCBs can completely replace traditional fuses and have the following advantages:

1. Reusable, only need to be reset after tripping, no need for replacement
2. Safer and more convenient operation
3. More stable protection characteristics, not affected by ambient temperature
4. Can be used as isolation switches

However, in some special applications, fuses still have their unique advantages, such as:

1. For protection scenarios requiring extremely fast breaking speed
2. For precision protection of certain electronic equipment
3. In extremely space-limited scenarios

Overall, for ordinary home electrical protection, MCBs are a better choice than fuses.

How do I calculate the rated current for the main incoming line MCB?

Methods for calculating the rated current of the home main incoming line MCB:

1. Based on Supply Capacity: Calculate based on the power capacity approved by the power supply department. For example, if the approved capacity is 7kW, then at 220V voltage, the current is about 32A, so a 40A MCB can be selected.
2. Based on Actual Load: Estimate the total power of appliances that may be used simultaneously in the home, then divide by the voltage to get the current. For example, if the estimated maximum simultaneous electrical load is 10kW, then at 220V voltage, the current is about 45A, so a 50A or 63A MCB can be selected.
3. Based on Branch Circuit MCBs: The rated current of the main MCB should be greater than the sum of the rated currents of all branch circuit MCBs multiplied by a demand factor (usually 0.6-0.8, as not all appliances will be used simultaneously).

Ordinary homes (three bedrooms) typically choose 40A-63A main MCBs, while larger homes may need 63A-80A or larger.

Why can’t an MCB be immediately closed after tripping?

An MCB cannot be immediately closed after tripping for the following possible reasons:

1. Fault not cleared: If the overload or short circuit fault that caused the trip still exists, the MCB will trip again
2. Thermal-magnetic element not cooled: After an MCB trips, the internal thermal-magnetic element needs some time to cool down to restore normal working status
3. MCB internal mechanical locking: Some MCBs are designed with mechanical locking functions to prevent frequent operations
4. MCB damage: If internal elements of the MCB are damaged during the tripping process, it may not close normally

Correct approach: After an MCB trips, first investigate and clear the fault cause, wait a few minutes for the MCB to cool down, then try to close it. If multiple attempts fail to close it, the MCB may need to be replaced.

Do home MCBs need to be replaced periodically?

Home MCBs do not need to be replaced at fixed intervals, but should be considered for replacement based on the following situations:

1. Used for over 15-20 years
2. Obvious aging, deformation, or discoloration in appearance
3. Inflexible operation or abnormal sounds
4. Frequent unexplained tripping or inability to trip normally
5. Significant increase in home electrical load, making existing MCB specifications no longer suitable
6. After severe short circuit events (even if the MCB still works, internal damage may have occurred)

Recommendation: Regularly check the working status of MCBs, promptly replace them if abnormalities are found; consider replacing old MCBs during large-scale renovation of the home electrical system.

XII. MCB Selection Calculator

Summary

Choosing the right MCB is an important step in ensuring home electrical safety. Through this article, we have learned about the basic concepts, working principles, key parameters, and selection methods of MCBs. When choosing MCBs, multiple factors need to be comprehensively considered, including circuit type, load current, wire specifications, tripping curve type, etc., to select the most suitable product.

Remember the following core principles:

1. The rated current of the MCB should be greater than or equal to the design load current of the circuit, but should not exceed the safe current-carrying capacity of the wire
2. Choose the appropriate tripping curve type based on load characteristics; Type B or C is generally selected for home circuits
3. Choose the appropriate number of poles based on the importance of the circuit and safety requirements
4. Choose an MCB with sufficient breaking capacity; ordinary homes generally choose 6kA or above
5. Prioritize well-known brands and certified products

Finally, although this article provides a detailed selection guide, for complex electrical systems, it is still recommended to consult the opinions of professional electricians or engineers to ensure the selection of the most suitable MCBs, providing reliable protection for home electrical safety.