This makes them easy to reach and safe to use. Place outdoor boxes at least 3 feet above the ground. This height also safeguards the box from potential water spills or accidental impacts. Adhering to these guidelines during the installation of a distribution box ensures. FIRE ALARM VISUAL ONLY DEVICE OR A COMBINATION AUDIBLE AND 80" TO BOTTOM OF DEVICE OR NOT MORE THAN 96" TO TOP. VISUAL DEVICE NOT LESS THAN 90" TO TOP OR 6" BELOW CEILING, WHICH EVER IS HIGHER. 54" TO DIAL CENTER (NON-ACCESSIBLE). 48" TO. Typical wall-mount enclosure sizes often range from about 200 × 200 × 120 mm up to 800 × 600 × 300 mm. Freestanding cabinets commonly range from about 1600–2200 mm in height, 600–1800 mm in width, and 300–600 mm in depth. The right size depends on internal layout, cable entry space, bend radius. Electrical box dimensions typically refer to: Correct dimensions ensure: Single-gang boxes are the most common type, used for one switch or outlet. Common uses: wall outlets, light switches, low-voltage controls. Tip: Depth is. BS 7671 requires that a socket-outlet on a wall or similar structure is mounted at a sufficient height above the floor or any working surface to minimize the risk of mechanical damage to the socket-outlet or to an associated plug and flexible cord during insertion, use or withdrawal of the plug. The dimension for height of working space for equipment operating at 600 volts (V), nominal, or less to ground and likely to require examination, adjustment, servicing or maintenance while energized shall comply with the 110.