What is an Air Switch?
Compared with traditional power switches, an air switch serves as a controller within low-voltage power distribution networks and electric drive systems. Its usage highlights control and protection functions, safeguarding electrical equipment sections or loads when circuits are fully engaged or broken. Additionally, it is particularly suitable for initiating ground starter motors. The working principle of an air switch involves automatically cutting off the circuit when the working current surpasses the rated current, in cases of short circuits, voltage loss, etc.
Air Switch Symbol
In circuit diagrams, the air switch is generally denoted by “QS.”
Principle of the Air Switch
The principle lies in the generation of relatively high heat when the circuit’s current exceeds the rated current. The thermal element within the air switch detects abnormal heat, triggering the air switch to open the circuit, thereby protecting it.
Differences Between Air Switch and Leakage Protector
Though visually similar, air switches and leakage protection devices differ in functionality. While air switches primarily protect circuits and electrical appliances, leakage protectors focus on ensuring personal safety. Leakage protectors are larger in size than air switches, often occupying 3P installation positions compared to the latter’s 1P or 2P.
Difference Between Circuit Breaker and Air Switch
The air switch models/specifications include:
- C65N 1P: C1A, C2A, C4A, C6A, C10A, C16A, C20A, C25A, C32A, C40A, C50A, C63A
- C65N 2P: C1A, C2A, C4A, C6A, C10A, C16A, C20A, C25A, C32A, C40A, C50A, C63A
- C65N 3P: C1A, C2A, C4A, C6A, C10A, C16A, C20A, C25A, C32A, C40A, C50A, C63A
- C65N 4P: C1A, C2A, C4A, C6A, C10A, C16A, C20A, C25A, C32A, C40A, C50A, C63A
- C65N 1P: D1A, D2A, D4A, D6A, D10A, D16A, D20A, D25A, D32A, D40A, D50A, D63A
- C65N 2P: D1A, D2A, D4A, D6A, D10A, D16A, D20A, D25A, D32A, D40A, D50A, D63A
- C65N 3P: D1A, D2A, D4A, D6A, D10A, D16A, D20A, D25A, D32A, D40A, D50A, D63A
Household Air Switch Configuration Scheme
- Living room and dining room sockets should connect directly to the air switch, preferably using 4 square lines, with a recommended air switch rating of 20A.
- Multiple bedroom sockets can share a single line, with 2.5 square meters to 4 square meters wires recommended, and a 20A air switch.
- The living room’s standalone air conditioner requires a dedicated line, typically with 6 square wires and a 25A air switch.
- The kitchen should have a separate line due to high-power appliances like range hoods and microwaves, using either 2.5 square meters or 4 square meters wires with leakage protection.
- The bathroom, requiring minimal electricity, can have a dedicated water heater line using 4 square wires and a 25A air switch with leakage protection.
- All lighting can share a single line using 1.5 square wire, with a 16A air switch being sufficient.
- A 40A or 63A total ACB is recommended, with branches usually running 6 ways. Consider using ACBs with leakage protection for kitchen, bathroom, and air conditioner.
Precautions for Choosing an Air Switch
- Select air switches between 1.5-2.5 times the rated current of the load, adjusting for frequent or heavy startups.
- Ensure authenticity of logos and external fonts, material and handle color distinctions, and presence of relevant standards marks on the switch surface.
Air Switch Wiring Installation
- Follow the scientific configuration method: main switch primary circuit, lighting primary circuit, living room, first bedroom socket circuit, first kitchen circuit, toilet socket, and each air conditioner circuit.
- Example: For a 2P air conditioner circuit with a DPN20A circuit breaker, the maximum allowed power is 4400W (220V*20A). Considering sudden increases in power during startup, a 20A circuit breaker suffices for a 2-horse air conditioner, rated at 2000W.
Specifications of Distribution Box
Distribution box rules include 12-bit, 16-bit, 20-bit, and 24-bit configurations, with one bit equaling the width of a 1P circuit breaker or a DPN circuit breaker (18mm).
Installation Suggestions
- Install switches at a height of 1.4M from the ground and 0.2M from doors where appropriate.
- Socket installation height varies by room: 30CM for living rooms, 1.4M for kitchens/bathrooms, and 1.8M for air conditioner sockets.
- When installing power sockets, ensure correct wiring and proper grounding.
- Install waterproof boxes for switches and sockets in bathrooms and open balconies to prevent water damage.
- Ensure bedside sockets are accessible and not blocked by furniture.
How to Install an Air Switch
- Prepare necessary tools, turn off the power supply, and place the power supply box in the reserved wall space.
- Arrange air switches neatly in the card slot and begin wiring, following the “top in and bottom out, left zero and right fire” principle.
- Connect household lines to the main power switch’s air switch, then connect lines to individual air switches based on appliance power.
- Label each circuit for easy identification during use and maintenance.
Installation Precautions
- Check home power supply method and appliance power requirements before installation.
- Purchase suitable air switches and connect them to the distribution box.
- If no distribution box exists, use a card slot for mounting the air switch securely to a wall or wooden board.
Troubleshooting Air Switch Trips
- If the shunt switch trips, adjust high-power electrical circuits or replace the air switch with a larger load.
- If the main switch trips, calculate appliance power to ensure it does not exceed approved capacity. Professional maintenance may be required for line issues.
Dealing with Leakage Switch Trips
- Adhere to safety practices when using household electricity, such as avoiding overloading power cords and ensuring proper insulation.
- Use qualified power cords, plugs, and sockets to prevent accidents, and maintain sufficient distance from high-voltage transmission lines.
- Follow correct wiring procedures and seek professional assistance when in doubt.
- Equip household appliances with qualified leakage protectors for personal safety.