The combination of air switches (air switches) in the distribution box varies according to different needs and scenarios.
Here are some common pairing schemes:
◆The main switch is equipped with a leakage protector, and all branches are equipped with 1P small air switches. This method has low cost and requires small space, but when there is a leakage fault in the branch, the main switch will trip, causing power outage in all branches and making maintenance more troublesome.
◆The main switch uses a leakage protector, and all branches use 2P air switches. This method requires slightly more space and costs compared to the former, but it eliminates the need for zero line wiring. When there is a leakage fault, the main switch will trip, and maintenance is still quite troublesome. When there is an overload or short circuit fault in the branch, only the branch air switch will be tripped, which is convenient for separate maintenance.
◆The main switch uses an air switch, and all branches use leakage protectors. This combination is more reasonable, slightly more expensive, and takes up more space. When there is a fault such as overload, short circuit, or leakage in the branch, only the switch of the branch should be tripped, which does not affect the use of other branches and is convenient for maintenance.
In addition, the selection of hollow openings in distribution boxes should consider the following factors:
◆ The same brand or series of products should be used to ensure safety and compatibility.
◆Select different types and specifications of air switches based on the different properties and uses of electrical equipment to improve the flexibility and reliability of the distribution system.
◆The rated current of the air switch should not be less than the rated current of the electrical equipment, and a certain load margin should be reserved.
◆The rated voltage of the air switch should match the rated voltage of the electrical equipment.
In actual installation, the distribution box should be equipped with a reasonable air switch circuit to avoid concentrated high-power electrical equipment circuits being protected by the same air switch.
The above plan is for reference only, and the specific combination should be determined based on actual needs and situations.