Fuses for home use have now been replaced by automatic mini circuit breakers, which are usually installed in a home distribution box. According to the electrical wiring, the switchgear, measuring instruments, protective electrical appliances and auxiliary equipment are required to be assembled in closed or semi enclosed metal cabinet or on the screen to form a low-voltage distribution box. In normal operation, the circuit can be connected or disconnected by manual or automatic switch. The power distribution cabinet distributes the electric energy of a circuit of the upper power distribution equipment to the nearest load. This equipment shall provide protection, monitoring and control of the load. The power cabinet is a combination of electrical control cabinets that provide power for the normal operation of the whole machine, including fuses, circuit breakers, contactors, frequency converters, high-voltage cabinets, transformers, etc. When the line or household appliances are short circuited or overloaded, it can automatically trip off and cut off the power supply, which plays the role of protecting the circuit and electrical appliances.

The household distribution box has single pole and double pole (single opening and double opening). The single pole occupies one position in the distribution box, and the double pole occupies two positions in the distribution box. In general, the main switch, i.e. the main switch, is of bipolar type. The switch controls the fire extinguishing, and the zero line. The other branches are basically unipolar open-air. The switch is connected to the fire-fighting line. The two pole switch is the fire-fighting line, and the zero line terminal block is not disconnected through the empty line. No open can only play the role of overload protection, but there is no leakage protection function. If leakage protection needs to be installed, there are two ways of single pole opening plus leakage protection in the distribution box. Only when there is no electricity can the electric protector really protect personal safety. Therefore, when combined with a well grounded ground wire, the empty switch with leakage protector should often check whether the leakage protector is effective. Generally, press the above test button every month, if it can be disconnected immediately, it will be replaced.

It is very important to correctly select the rated capacity current. It should be noted that the nominal value of air switch depends on the usage of electrical appliances and the size of wires in the future. It can not be too large or too small. If the rated current of air switch is too small, it is easy to trip frequently and cause unnecessary power failure. If it is too large, the expected protection effect can not be achieved.

The air switch system used in home installation is common. The product specifications of different models are C10, C15, C20, C25, C32, etc. generally, C32 can be installed for 6000W speed thermoelectric water heater. To install 7000w-8500w electric water heater is to use larger air to pass through the switch and go through a separate circuit. Therefore, we are generally old houses and can not use some high-power high-speed thermoelectric water heaters.