An 18-circuit distribution box typically measures 335 × 225 × 110 mm (L×W×H).

The HT-18 waterproof distribution box, designed for 18 circuits in a single-row layout, has overall dimensions of 335 mm in length, 225 mm in width, and 110 mm in height. It features a side-opening hinged cover and is made of ABS/PC materials, making it suitable for both indoor and outdoor applications with an IP65 protection rating . This size accommodates 18 MCBs or RCBOs in a single row, with additional space for neutral and earth bars.

Key Considerations

• Circuit Layout: The 18 circuits are arranged in a single row, with 12 holes for the zero row and 12 holes for the ground row, ensuring organized wiring .
• Mounting: Wall-mounted installation is standard, and the box provides sufficient internal space for cable entry, bend radius, and future expansion .
• Protection and Material: IP65 rating ensures dust-tight and water-resistant protection, suitable for outdoor or harsh environments. The ABS/PC construction provides durability and impact resistance .
• Standards Compliance: Distribution boxes should comply with IEC 61439 and other regional electrical standards for safety and performance .

Practical Tips

• Always verify the internal usable space before installation, as wall thickness, busbars, and mounting hardware reduce the effective area for wiring .
• Consider leaving 10–20% spare capacity for future circuit additions or modifications .
• For outdoor installations, ensure proper sealing and cable gland selection to maintain the IP65 rating . This size is typical for residential, commercial, or light industrial applications requiring 18 outgoing circuits, providing a balance between compact footprint and sufficient wiring space.