Standard dimensions for fire protection distribution boxes

Fire protection distribution boxes, such as M-BOX and L-BOX, typically range from 140x190x86 mm to larger configurations depending on terminal block capacity and fire resistance requirements.

M-BOX Dimensions

The M-BOX series is designed for fire-resistant wiring and continuous operation during fire conditions. Typical dimensions for standard M-BOX units are 140 mm (width) x 190 mm (height) x 86 mm (depth). These boxes are made of polycarbonate, halogen-free material, and provide a high degree of protection with IP65 rating. They can be mounted on ceilings or cable trays and operate in temperatures from -25°C to 55°C. Connector orientations can be horizontal or oblique, with terminal block counts ranging from 4 to 10 depending on the model .

L-BOX Dimensions

L-BOX units are larger and allow for more terminal blocks and connectors. Standard dimensions are similar in width and height to M-BOX but can vary slightly depending on configuration. For example, L-BOX models support up to 16 terminal blocks and multiple connectors, with weights ranging from 510 g to 660 g. They maintain electrical functions under fire conditions rated E30 to E90 and also feature IP65 protection. Connector orientation can be horizontal or oblique, and the boxes are suitable for ceiling or wall mounting .

Additional Features

• Through holes: Typically 8x25 mm and 2x20 mm for cable entry .
• Fuse integration: Line fuses for overvoltage protection are compact, around 27x21x28 mm, and can be mounted inside M-BOX or L-BOX .
• Mounting kits: Designed for embedding in concrete or natural stone, with minimum depth and diameter specifications to ensure secure installation .

Summary

In practice, fire protection distribution boxes are compact but robust, with dimensions generally around 140x190x86 mm for smaller M-BOX units, and larger L-BOX units accommodating more terminal blocks and connectors. They are designed to maintain electrical functionality during fire events, provide IP65 protection, and allow flexible mounting options .