What are the precautions for installing air switches and residual current circuit breakers in the ho
The following are the precautions during the installation process of air switches and residual current circuit breakers in the household main distribution box:
### I. Safety aspects
1. **Power-off operation**
- Before installation, be sure to cut off the total power supply of the household. This can be achieved by turning off the main switch at the electricity meter box. Moreover, the lines in the distribution box should be tested with a voltage tester before the operation to ensure that there is no electricity before starting the installation work. This is to prevent electric shock accidents, because even if the main switch is turned off, there may still be induced electricity or other unexpected electrified situations.
2. **Personal protection**
- Installers should wear insulating gloves and insulating shoes to provide additional safety protection. Insulating gloves can prevent hands from getting an electric shock when directly touching electrified parts, and insulating shoes can reduce the possibility of electric current passing through the human body in case of accidental contact with electrified objects.
### II. Selection aspects
1. **Reasonable selection of capacity**
- Select the rated current of air switches and residual current circuit breakers according to the total power of household electrical equipment. Generally speaking, the total household switch can estimate the total current according to 5 - 7 amperes per kilowatt of power. For example, if the total power of household electrical equipment is 10kW, the total current is approximately 50 - 70A. At this time, a total switch of about 60A can be selected. For branch circuits, switches of 10 - 16A are generally selected for lighting circuits, switches of 16 - 20A are selected for socket circuits, and appropriate switches are separately selected for circuits of high-power electrical appliances such as air conditioners according to their power.
- Meanwhile, it is necessary to consider the possible addition of electrical equipment in the future and reserve a certain capacity margin to avoid frequent replacement of switches.
2. **Compatibility**
- The leakage operating current and operating time of the residual current circuit breaker should meet the requirements of household electrical safety. Generally, the leakage operating current of household residual current circuit breakers is 30mA, and the operating time does not exceed 0.1 seconds. This is because the safe current that the human body can withstand is generally below 30mA. Such parameter settings can cut off the power supply in time when leakage occurs to protect personal safety. Moreover, it is necessary to ensure that the rated voltage and frequency of the residual current circuit breaker match the voltage and frequency of the household power grid. For example, the household electricity in China is generally 220V, 50Hz, so the equipment with corresponding parameters should be selected.
### III. Installation location and environment aspects
1. **Location selection**
- The distribution box should be installed in a dry place with good ventilation and convenient for operation and maintenance. Avoid installing it in damp areas such as basements, bathrooms, and kitchens that are prone to water accumulation, because a damp environment may cause electrical equipment to be damaged by moisture, and even lead to short circuits and electric shock accidents.
- The installation location should also avoid direct sunlight and high-temperature environments, because excessive temperature will affect the performance and service life of electrical equipment. Generally speaking, the ambient temperature around the distribution box should be between - 5℃ and 40℃.
2. **Space requirements**
- Sufficient space should be left inside the distribution box to facilitate the installation, wiring, and heat dissipation of air switches and residual current circuit breakers. A certain distance should be maintained between switches to avoid mutual influence during operation or in case of failure. Meanwhile, the wiring of electric wires should be neat and orderly and not too messy to avoid short circuits or difficulties in maintenance.
### IV. Installation operation aspects
1. **Installation of the rail**
- When installing the rail, make sure that the rail is firmly fixed and level. It can be detected with a level gauge, and the deviation should not exceed the specified range. Because if the rail is not level, the air switches and residual current circuit breakers installed on it may tilt, affecting their normal operation and the stability of the connection.
2. **Wiring operation**
- When connecting electric wires, strictly follow the wiring marks on the air switches and residual current circuit breakers. Generally speaking, the power supply incoming wire is connected to the upper end of the switch, and the outgoing wire is connected to the lower end. For multi-strand conductors, they should be tightly twisted together before being inserted into the terminal hole, and it is necessary to ensure that the insertion depth is sufficient, and then tighten the screw to ensure a good electrical connection between the conductor and the terminal post.
- During the wiring process, avoid the insulation sheath of the electric wire from entering the terminal hole to avoid affecting the conductive performance or causing a short circuit. Meanwhile, electric wires of different phase sequences (such as live wire, neutral wire, and ground wire) should be connected according to the specified colors and positions for the convenience of future maintenance.
3. **Installation sequence**
- Generally, air switches are installed first, and then residual current circuit breakers are installed. Because air switches are mainly used for overload and short-circuit protection, while residual current circuit breakers focus on leakage protection and play different roles in the circuit. Moreover, during the installation process, attention should be paid to preventing dust, debris, etc. from entering the inside of the switches and affecting their performance.
