What circuits are generally divided in a household distribution box?

The circuit division of a household distribution box needs to be reasonably configured according to the 

household power consumption demand, electrical appliance power, and safety. The common standard circuit 

types and configuration key points are as follows:

### I. Basic Circuit Configuration

#### 1. Lighting Circuit

- **Function**: Control the lighting fixtures throughout the house (chandeliers, downlights, wall lamps, etc.).

- **Configuration**:

  - Wire: 1.5-2.5mm² copper core wire (single-strand hard wire or multi-strand soft wire).

  - Circuit breaker: 16A single-pole circuit breaker.

- **Characteristic**: The lighting power is relatively low (usually ≤ 2000W), and the same circuit can be shared.

#### 2. Common Socket Circuit

- **Function**: Wall sockets in areas such as the living room and bedroom (TVs, computers, table lamps, etc.).

- **Configuration**:

  - Wire: 2.5mm² copper core wire.

  - Circuit breaker: 20A double-pole residual current circuit breaker (to prevent electric shock).

- **Note**: It is recommended that the number of sockets in a single circuit is ≤ 10 to avoid overloading.

#### 3. Kitchen Socket Circuit

- **Function**: Kitchen appliances (refrigerators, microwaves, rice cookers, ovens, etc.).

- **Configuration**:

  - Wire: 4mm² copper core wire (because kitchen appliances have high power and may be used simultaneously).

  - Circuit breaker: 32A double-pole residual current circuit breaker.

- **Special Requirement**: It is recommended that the refrigerator has a separate circuit to ensure that the 

refrigerator can still operate when other circuits trip.

#### 4. Air Conditioner Circuit

- **Function**: Wall-mounted/cabinet air conditioners.

- **Configuration**:

  - Wire: 4mm² copper core wire (2.5mm² can be used for air conditioners below 1.5 horsepower).

  - Circuit breaker: 20-32A single-pole circuit breaker (specifically according to the power of the air conditioner).

- **Note**:

  - Each air conditioner should have a separate circuit (especially for cabinet air conditioners).

  - The starting current of inverter air conditioners is relatively small, and the specification of the circuit breaker 

can be appropriately reduced.

YouTube：https://youtube.com/shorts/KMoHnv28L5c

#### 5. Bathroom Circuit

- **Function**: Bathroom sockets (electric water heaters, hair dryers, smart toilets, etc.).

- **Configuration**:

  - Wire: 4mm² copper core wire (due to the high power of electric water heaters).

  - Circuit breaker: 32A double-pole residual current circuit breaker.

- **Safety Requirement**: A residual current protector must be used and isolated from other circuits.

### II. Advanced Circuit Configuration (Selected According to Requirements)

#### 6. Dedicated Circuit for Electric Water Heater

- **Function**: Instantaneous electric water heaters (power ≥ 6000W).

- **Configuration**:

  - Wire: 6mm² copper core wire.

  - Circuit breaker: 40A single-pole circuit breaker.

- **Characteristic**: It requires an independent circuit to avoid mixing with other electrical appliances.

#### 7. Electric Vehicle Charging Circuit

- **Function**: Home charging piles (below 7kW).

- **Configuration**:

  - Wire: 6mm² copper core wire (if the power of the charging pile is higher, it needs to be upgraded to 10mm²).

  - Circuit breaker: 40A double-pole residual current circuit breaker.

- **Note**: The circuit needs to be planned in advance to avoid wet areas.

#### 8. Smart Home Circuit

- **Function**: Low-power devices such as smart speakers, cameras, and electric curtains.

- **Configuration**:

  - Wire: 1.5-2.5mm² copper core wire.

  - Circuit breaker: 16A single-pole circuit breaker.

- **Characteristic**: It can be combined with the lighting circuit, but it is recommended to set it separately 

for easy management.

#### 9. Spare Circuit

- **Function**: For newly added electrical appliances in the future or temporary power consumption.

- **Configuration**:

  - Wire: 4mm² copper core wire.

  - Circuit breaker: 32A single-pole circuit breaker.

- **Suggestion**: Reserve 2-3 spare circuits for easy expansion.

### III. Circuit Configuration Principles

1. **Power Matching**

   - Calculate the current according to the total power of the electrical appliances:

     \[

     I = \frac{P}{U} \quad (\text{Under a voltage of 220V, } P\text{ is in watts})

     \]

   - The current-carrying capacity of the wire should be ≥ 1.2 times the calculated current (refer to the

 formula for the current-carrying capacity of copper busbars).

2. **Safety Protection**

   - Residual current circuit breakers must be used in socket circuits (operating current ≤ 30mA).

   - Strengthen the insulation in wet areas such as the kitchen and bathroom.

3. **Regional Control**

   - Different areas (such as the bedroom and living room) can be controlled by separate circuits to avoid 

a power outage throughout the house due to a fault in one place.

### V. Precautions

1. **Wire Selection**: Give priority to flame-retardant insulated copper core wires (such as BV wires).

2. **Installation Specifications**:

   - The phase wire (L), neutral wire (N), and ground wire (PE) need to be strictly distinguished.

   - The distribution box needs to be grounded, and the cross-sectional area of the ground wire should

be ≥ 50% of that of the phase wire.

3. **Local Standards**: Refer to the "Code for Design of Residential Buildings" GB 50096 and local 

electrical safety regulations.

It is recommended that professional electricians design the circuits of the distribution box according to

 the house area, electrical appliance power, and personalized needs to ensure the safety and convenience of electricity use.