Distribution boxes vary in type, material, dimensions, and number of ways, with specifications ranging from small 1-way plastic boxes to large 36-way metal enclosures.

Types and Materials

Distribution boxes are generally made from steel plates or flame-resistant ABS plastic, with insulating plates also acceptable. Wooden materials are not recommended due to safety concerns . Plastic boxes are commonly used for residential and commercial applications, while metal boxes are preferred for industrial or high-load environments .

Dimensions and Number of Ways

Distribution boxes are available in a wide range of sizes and configurations:

• Plastic series (HA, HK, LGD, MB-ABC, MB-AF, MB-AS, MB-LF):
  • Length: 100–415 mm
  • Width: 105–323 mm
  • Height: 75–140 mm
  • Number of ways: 1–36
• TOP series (TOP-TS, TOP-TF, TOP-LS, TOP-PS, TOP-PF, TOP-S):
  • Configurations range from 1-way to 36-ways
  • Dimensions include length, width, and height, varying by model
• Industrial single-phase boards (e.g., JUNON C6 series):
  • Include cover, frame, base box, guide rail, neutral and earth copper bars
  • Available in surface mounting or flush mounting types

Installation Guidelines

• Fixed boxes: Bottom should be 1.3–1.5 m above ground
• Mobile boxes: Bottom should be 0.6–1.5 m above ground
• Spacing: Distance between distribution and switch boxes should not exceed 30 m; horizontal distance to fixed equipment should not exceed 3 m
• Safety: Each box must have its own switch and RCD (rated ≤30 mA, operating time ≤0.1 s)
• Mechanical: Boxes must be installed straight, firmly, and locked; no temporary equipment or sundries should be placed inside

Features

• Flame-proof, impulse-proof, and excellent insulation properties for plastic boxes
• Modular design allows combination of multiple units
• Compliance with standards such as BS EN60439-3 and JB/T7121-93

Summary

Distribution boxes are selected based on application, number of ways, material, and mounting type. Plastic boxes are suitable for residential and commercial use, while metal boxes are preferred for industrial applications. Dimensions and configurations follow a sequence from small 1-way units to large 36-way enclosures, ensuring flexibility in electrical distribution design .