Primary distribution boxes typically range from 200–415 mm in length, 105–323 mm in width, and 75–140 mm in height depending on the series and number of ways.

Common Dimensions by Series

• MB-ABC Series:
  • MB-ABC500: 200 mm (L) × 174 mm (W) × 95 mm (H)
  • MB-ABC700: 255 mm (L) × 172 mm (W) × 95 mm (H)
  • MB-ABC900: 328 mm (L) × 172 mm (W) × 95 mm (H) These boxes are made of flame-resistant ABS plastic and are suitable for AC 50Hz, 220V/380V circuits in residential and commercial buildings .
• HA, HK, LGD Series:
  • Length: 100–415 mm
  • Width: 105–323 mm
  • Height: 75–140 mm These series provide modular options for different numbers of ways and installation requirements .
• TOP Series (TOP-TS, TOP-TF, TOP-LS, TOP-PS, TOP-PF, TOP-S):
  • Designed for 1-way to 36-ways
  • Dimensions vary according to the number of ways and mounting requirements, generally within the ranges above .

Material and Standards

Primary distribution boxes are typically made from engineering thermoplastics such as ABS, Polycarbonate (PC), or ASA, or from powder-coated stainless steel for industrial applications. They comply with standards like IEC 61439, IEC 60670, BS EN60439-3, and local electrical codes .

Selection Considerations

When choosing a primary distribution box, consider:

• Number of outgoing circuits and spare ways for future expansion
• Internal layout: busbars, neutral and earth bars, DIN rail space
• Enclosure protection: IP rating, UV resistance, impact resistance
• Installation environment: indoor, outdoor, residential, commercial, or industrial These dimensions and specifications ensure proper fit, safe installation, and compliance with electrical standards.