Location of the third-level distribution box

The third-level distribution box, or switch box, is installed close to the electrical equipment it controls, typically within 3 meters horizontally, and in a ventilated, dry, and safe area.

Location Relative to Other Distribution Levels

The third-level distribution box is the final stage in a three-level power distribution system. It receives power from the second-level distribution box and directly supplies electrical equipment, either a single device or a group of similar devices . Unlike the main or secondary distribution boxes, it is closely connected to the equipment it controls, ensuring efficient and safe power delivery .

Distance Requirements

• The horizontal distance between the switch box and the fixed electrical equipment it controls should not exceed 3 meters .
• The distance from the second-level distribution box should generally be less than 30 meters to maintain proper voltage and safety standards .

Installation Environment

• Must be installed in a ventilated, dry, and normal temperature location.
• Avoid areas with gas, smoke, steam, liquids, vibration, impact, or heat sources that could damage the box or equipment .
• A clear workspace around the box is required for safe operation and maintenance, free from obstacles, weeds, or debris .

Construction and Safety Considerations

• The box should be made of iron or high-quality insulating material, with a minimum thickness of 1.5 mm for metal panels .
• Electrical equipment inside should be mounted on metal or non-wood insulating boards and securely fastened to the box shell.
• Proper grounding and electrical connections between the metal plate and the switchboard shell are essential for safety .

Summary

The third-level distribution box is installed near the end-use electrical equipment, within 3 meters horizontally, and in a safe, ventilated, and dry location. It is the final control and protection point in the three-level distribution system, ensuring reliable and safe power delivery to individual devices or equipment groups .