Large horizontal distribution boxes typically range from 328–900 mm in length, 172–323 mm in width, and 95–140 mm in height, depending on series and number of ways.

Typical Dimensions

• MB-ABC Series: Length 200–328 mm, Width 172–174 mm, Height 95 mm, supporting multiple modular ways for residential and commercial circuits .
• HA, HK, LGD Series: Length 100–415 mm, Width 105–323 mm, Height 75–140 mm, suitable for larger horizontal configurations .
• TOP Series (TOP-TS, TOP-TF, TOP-LS, TOP-PS, TOP-PF, TOP-S): Designed for 1-way to 36-way setups, with dimensions varying according to the number of ways and mounting requirements .

Features and Standards

• Material: Most large horizontal boxes are made of flame-resistant ABS plastic or metal, ensuring compliance with safety standards such as BS EN60439-3 and IEC regulations .
• Mounting: Boxes often include adjustable studs, nuts, and gland plates for easy installation and modular expansion .
• Capacity: Designed to accommodate multiple MCBs, RCCBs, or other modular components, with generous wiring space for horizontal layouts .
• Protection Ratings: Many industrial and retrofit boxes offer high IP ratings (IP44–IP67) for dust and water resistance, suitable for indoor and outdoor installations .

Considerations for Selection

• Number of Ways: Choose a box that matches the number of circuits required; larger horizontal boxes support up to 36 ways .
• Future Expansion: Consider boxes with removable top/bottom extensions or pre-wired options for future upgrades, especially for EV charging or smart home systems .
• Compliance: Ensure the box meets local electrical codes (NEC, IEC) and fire safety standards for the intended application . By selecting a box based on these dimensions and features, installers can ensure proper fit, safety, and flexibility for both residential and commercial electrical distribution needs.