Distribution box electrical components selection configuration - Database & Sql Blog Articles

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1. The main distribution box must be equipped with power isolation, normal connection and disconnection functions, as well as protection against short circuits, overloads, and leakage. It typically consists of one incoming unit and one or more outgoing units. It should include a transparent molded case circuit breaker with a visible break point, and an auxiliary power-type residual current device (RCD) that can automatically disconnect when the auxiliary power fails. Each output loop should have a three-point terminal block for easy identification and maintenance. 2. The total number of distribution circuits in the main distribution box (distribution cabinet) should range from 1 to 5 loops, depending on the application requirements. 3. The distribution electric box includes one incoming line unit and several outgoing units. It is fitted with a transparent molded case circuit breaker for the main switch and sub-switches, both with visible break points. A five-point terminal block is also installed for each circuit to ensure proper wiring and safety. 4. The number of distribution circuits in the distribution electric box should be between 2 and 7, allowing flexibility for different electrical needs. 5. The switch box contains an incoming line unit and an outgoing line unit. It is equipped with a transparent molded case circuit breaker and a leakage protector with visible break points, along with a five-point terminal block for secure connections. 6. The transparent molded case circuit breakers in the main distribution box, distribution electric box, and the visible break points in the switch box should all be located at the power input end for better visibility and control. 7. The main distribution box must be fitted with a voltmeter, a total ammeter, and a watt-hour meter. These instruments must not share a current transformer. When installing a current transformer, the secondary circuit must have a grounding point connected to the protective neutral wire, and it is strictly prohibited to open this circuit during operation. 8. The rated leakage current of the RCD in the main distribution box should be greater than 30 mA, and the rated leakage operation time should be more than 0.1 seconds. However, the product of the rated leakage current and the rated leakage operation time must not exceed 30 mA·s to ensure safe and efficient operation. 9. In the switch box, the rated leakage current of the RCD should not exceed 30 mA, and the rated leakage operation time must not be longer than 0.1 seconds, providing quick response to potential faults. 10. It is strictly forbidden to use plug and socket connections for the power supply terminals of distribution boxes and switch boxes. Direct and secure wiring methods are required to prevent accidental disconnections or electrical hazards. 11. All distribution boxes and switch boxes should clearly display their name, purpose, shunt markings, and system wiring diagrams for ease of identification and proper installation.