The three-level distribution box can be connected

A three-level distribution box system must be connected hierarchically, with each level supplying the next, and the third-level box directly powering electrical equipment without bypassing intermediate levels.

In a three-level distribution system, connections must follow a strict hierarchy: the first-level distribution box (main distribution box) receives power from the source and distributes it to second-level distribution boxes, which in turn supply third-level distribution boxes or switch boxes that directly power electrical equipment . No equipment should be connected by bypassing any level, as this violates the structural and branching principles of the system .

• First-Level Distribution Box: Installed near the power source, it contains the main circuit breaker, leakage protector, voltmeter, and ammeter. It manages and monitors the entire site's power .
• Second-Level Distribution Box: Located near high-consumption areas or large equipment, it distributes power from the first-level box to third-level boxes and includes branch circuit breakers and leakage protectors .
• Third-Level Distribution Box: Also called the switch box, it is the final junction point supplying power directly to electrical equipment. It must include the last layer of leakage protection .

• Grounding: All distribution boxes and equipment must be connected to a protective zero line (PE) to ensure safety in case of leakage .
• Separate Circuits: Power and lighting circuits should be separated, with dedicated switch boxes for each .
• Distance Guidelines: The distance between distribution boxes and switch boxes should be minimized, ideally under 30 meters, and the distance from a switch box to its controlled equipment should not exceed 3 meters .
• Professional Management: Only qualified electricians should operate or modify the system, with regular inspections to ensure insulation, wiring integrity, and protection device functionality .

• Do not connect electrical equipment directly to the main or second-level boxes; always follow the hierarchical path.
• Each switch box should control only one piece of equipment to maintain safety and system integrity .
• Use proper grounding, leakage protection, and distance management to ensure operational safety.

Following these principles ensures that a three-level distribution box system is safe, reliable, and compliant with electrical standards.