Power supply distance of lighting distribution box

The main lighting distribution box should be installed close to the power supply, with a maximum distance of 3 meters to the controlled electrical equipment and 30 meters between distribution boxes.

Recommended Distances

• From Power Supply to Distribution Box: The distribution box should be located near the power supply to minimize voltage drop and ensure efficient operation of connected lighting equipment. This proximity helps reduce cable losses and improves system reliability (source: ).
• Between Distribution Boxes: The horizontal distance between two distribution boxes should not exceed 30 meters to maintain proper voltage levels and facilitate maintenance (source: ).
• From Distribution Box to Controlled Equipment: The distance from the distribution box to the fixed electrical equipment it controls should not exceed 3 meters to ensure safe and effective power delivery (source: ).

Installation Considerations

• Environment: Install the distribution box in a ventilated, dry, and normal temperature area. Avoid locations with gas, smoke, steam, liquids, heat sources, vibration, or furnace splashes (source: ).
• Accessibility: Ensure sufficient space around the box for maintenance, typically allowing two people to work simultaneously. Avoid stacking objects or placing the box near weeds or bushes (source: ).
• Material and Protection: Use boxes made of iron sheet or high-quality insulating material with a minimum thickness of 1.5 mm. Ensure proper grounding and connection of all metal parts to the neutral line (source: ).
• Compliance: Follow local electrical codes, such as NEC, IEC, or other applicable standards, and ensure proper IP/NEMA ratings for indoor or outdoor use (source: ).

Summary

For safe and efficient lighting distribution, keep the distribution box close to the power source, maintain a maximum of 30 meters between boxes, and no more than 3 meters to the controlled equipment. Proper placement, ventilation, and compliance with standards are essential for long-term reliability and safety.