What are the reasons for the tripping of the air switch in the household distribution box?

What are the reasons for the tripping of the air switch in the household distribution box?

The reasons for the tripping of the air switch in the household distribution box are mainly related to

 **overload, short circuit, leakage, the air switch's own failure, and power distribution design**. The 

following are the specific analyses and troubleshooting suggestions:

### I. Tripping due to Overload

**Reasons**:

The total current of the circuit exceeds the rated current of the air switch. This is commonly seen in the 

following situations:

- Multiple high-power electrical appliances (such as air conditioners, electric water heaters, and induction 

cookers) **are operating simultaneously**.

- The wires are aging or of insufficient specification (for example, a **2.5mm² wire is matched with a C32

 air switch**, exceeding the safe current-carrying capacity).

- There is a fault in the electrical appliance (such as a short circuit in the winding of a motor-type device, 

resulting in an abnormal increase in current).

**Troubleshooting Methods**:

1. Disconnect all electrical appliances and close the switches one by one to locate the overloaded circuit.

2. Calculate the total power of the electrical appliances in this circuit: **Power (W) = Voltage (220V) ×

 Current (A)**. If it exceeds the rated current of the air switch (for example, a C25 air switch corresponds

 to 5500W), it is an overload.

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**Solutions**:

- Avoid sharing the same circuit for multiple high-power electrical appliances.

- Replace the air switch with a larger specification (the wire needs to be matched accordingly. For example, 

a 4mm² wire should be matched with a C32 air switch).

- Repair or replace the faulty electrical appliance.

### II. Tripping due to Short Circuit

**Reasons**:

The live wire directly contacts the neutral wire (or the ground wire), generating a very large current

 instantaneously. This is commonly seen in the following situations:

- The insulation layer of the wire is **aging and damaged**, **bitten by mice**, or **damaged during

 construction**.

- The copper pieces inside the socket/switch **fall off and overlap**.

- The internal components of the electrical appliance (such as capacitors and circuit boards) **are broken 

down and short-circuited**.

- The **humid environment** (such as in the bathroom) causes the circuit to leak and short-circuit.

**Troubleshooting Methods**:

1. Disconnect all electrical appliances and use the **resistance range** of a multimeter to measure the 

resistance of the circuit:

   - If the resistance between the live wire and the neutral wire is **0Ω or close to 0Ω**, there is a short circuit.

2. Disconnect the circuit in sections (such as sockets and lamps) to narrow down the scope of the short circuit.

**Solutions**:

- Replace the short-circuited wire or electrical appliance.

- Carry out **waterproof and insulating treatment** on the circuit in the humid area.

### III. Tripping due to Leakage (for air switches with leakage protection)

**Reasons**:

The current leaks through the human body, the ground wire, or a humid conductor. The leakage protector

 trips when it detects that the current difference between the live wire and the neutral wire is **> 30mA**. 

This is commonly seen in the following situations:

- The insulation of the electrical appliance is **damaged** (for example, the inner tank of an electric water

 heater leaks water and comes into contact with the circuit).

- The circuit is **affected by moisture** (for example, water enters the sockets in the bathroom or kitchen).

- The **ground wire is not connected or has poor contact**, resulting in the leakage current being unable

 to be led into the ground.

**Troubleshooting Methods**:

1. Use a **leakage tester** to detect the leakage value of the circuit.

2. Disconnect the branch air switches one by one. If the leakage protector no longer trips after a certain 

branch is disconnected, there is a leakage in this branch.

**Solutions**:

- Replace the leaking electrical appliance or repair the insulation layer.

- Check whether the connection of the ground wire is firm.

- Use **waterproof sockets** and **2P leakage protection switches** in the humid area.

### IV. Failure of the Air Switch Itself

**Reasons**:

- **Aging**: The internal spring or tripping mechanism fails, causing a false trip.

- **Quality problems**: The sensitivity of unbranded air switches is abnormal.

- **Loose wiring**: The terminal screws are not tightened, resulting in an increase in contact resistance 

and tripping due to heating.

**Troubleshooting Methods**:

1. Touch the surface of the air switch. If it is abnormally hot, it may be due to loose wiring or an internal fault.

2. Replace the air switch with the same specification and test whether it continues to trip.

**Solutions**:

- Tighten the wiring terminals to avoid oxidation.

- Select air switches from regular brands (such as Chint and Schneider).

### V. Unreasonable Power Distribution Design

**Reasons**:

- The rated current of the main switch is **less than the sum of the currents of the branch switches**, 

resulting in frequent tripping of the main switch.

- High-power electrical appliances (such as cabinet air conditioners) are not on a separate branch circuit 

and share the circuit with other electrical appliances.

- The **hierarchical configuration of the leakage protection switches is inappropriate** (for example, 

there is a conflict in sensitivity between the main leakage protector and the branch leakage protectors).

**Solutions**:

- Refer to the previous configuration scheme to ensure that **the current of the main switch ≥ the sum 

of the currents of the branch switches**.

- High-power electrical appliances ( > 3000W) should use a **4mm² wire + 2P air switch** separately.

### VI. Environmental Factors

**Reasons**:

- High temperatures in summer or **poor heat dissipation** of the distribution box lead to thermal 

tripping of the air switch.

- **Dust accumulation** inside the distribution box causes leakage or short circuit.

**Solutions**:

- Keep the distribution box ventilated and avoid direct sunlight.

- Clean the dust regularly and check the insulation of the circuit.

### Tripping Troubleshooting Flow Chart

1. **Reset the air switch**: If it trips immediately, give priority to troubleshooting **short circuits**.

2. **Close the switches one by one**: Test the branches to locate the faulty circuit.

3. **Measure the current/resistance/leakage current**: Use a multimeter or professional instruments for detection.

4. **Replacement method**: Replace the air switch or electrical appliance to confirm whether it is a device failure.

**Note**: If the air switch trips frequently and you cannot troubleshoot it yourself, it is recommended to 

contact a professional electrician to avoid the risks of electric shock or fire.