2)The distribution box shall be installed firmly, horizontal and vertical, and the vertical deviation shall not be greater than 3mm; During concealed installation, there shall be no gap around the distribution box, the edges around the panel shall be close to the wall, and the. 2)The distribution box shall be installed firmly, horizontal and vertical, and the vertical deviation shall not be greater than 3mm; During concealed installation, there shall be no gap around the distribution box, the edges around the panel shall be close to the wall, and the. 1)The distribution box shall be installed in a concealed way. The distribution box shall be embedded in the wall. When building the wall, the reserved hole shall be about 20mm larger than the length and width of the distribution box. Especially in certain areas, improper operations during installation may lead to serious consequences. For cases where the precautions were not followed, some corrective. The installation elements of panel electrical box include the following points: **Determine the installation location**: Choose a dry, well-ventilated location to install the panel distribution box, away from flammable and explosive items, and make sure there are no obstructions around it. It takes the incoming power and safely distributes it to different circuits throughout your building.