Original hole location of the distribution box

The original hole for a distribution box should be slightly larger than the box itself, embedded in the wall, and positioned for easy access and secure installation.

Hole Dimensions and Placement

When installing a distribution box in a concealed wall, the reserved hole should be about 20 mm larger than the length and width of the box to allow for proper fitting and plastering, with the depth equal to the thickness of the box plus the wall plastering thickness . This ensures the box sits flush with the wall surface and allows for finishing materials.

Fixing and Alignment

The box is typically fixed using split bolts (expansion bolts) or, for smaller boxes, wood bricks embedded at the installation site with screws . The installation must be firm, horizontal, and vertical, with a vertical deviation not exceeding 3 mm. For concealed installations, there should be no gaps around the box, and edges should be close to the wall, often coated with anti-corrosion paint for metal boxes .

Location Considerations

The distribution box should be installed in dry, accessible areas with good ventilation, typically at a height of around 1.5 meters from the floor for residential setups . Common locations include basements, utility rooms, garages, or mounted outside near the electrical meter . The position should avoid water, flammable, or corrosive substances and allow easy access for maintenance and future upgrades.

Summary

• Hole size: ~20 mm larger than the box dimensions
• Depth: Box thickness + plaster thickness
• Fixing: Expansion bolts or wood screws on embedded bricks
• Alignment: Horizontal and vertical, deviation ≤3 mm
• Location: Dry, accessible, ventilated, ~1.5 m height for residential use
• Wall finish: Flush with wall, edges coated if metal Following these guidelines ensures the distribution box is secure, accessible, and compliant with safety standards while allowing for proper wall finishing and maintenance .