Electrical mounting plate of distribution box

Electrical mounting plates provide a rigid, organized surface inside distribution boxes to securely install circuit breakers, DIN rails, busbars, and other modular devices.

Purpose and Function

A mounting plate, also called a back panel, subpanel, or mounting board, serves as the internal mechanical base for electrical components inside a distribution box or control panel. It allows devices such as circuit breakers, contactors, terminal blocks, relays, power supplies, and PLCs to be mounted without drilling directly into the enclosure walls, ensuring stability, serviceability, and proper grounding.

Materials and Construction

Mounting plates are typically made from galvanized steel (commonly 3 mm thick) for mechanical strength and corrosion resistance. Stainless steel is used in corrosive environments, while aluminum offers reduced weight and easier machining. For lighter-duty applications, high-grade plastic plates are also available.

Metal plates may require proper electrical bonding, while painted or anodized surfaces should not be assumed to provide continuity.

Dimensions and Compatibility

Mounting plates come in a variety of sizes, typically ranging from 250x200 mm to 500x500 mm, and are often pre-drilled to match specific enclosure models. They can be removable for easier assembly and wiring outside the enclosure, or fixed depending on the workflow and panel design.

Applications

These plates are essential in industrial, commercial, and residential electrical systems, including power distribution boards, motor control centers, and building management systems. They support heavy components like variable frequency drives and power supplies in industrial settings, and help organize lighting control or HVAC equipment in commercial installations.

Selection Considerations

When choosing a mounting plate, consider: Enclosure size and hole pattern to ensure proper fitMechanical load to support all installed devices without flexingEnvironmental factors such as humidity, chemicals, dust, and temperatureAssembly workflow, favoring removable plates for easier panel building Electrical mounting plates are a critical component for safe, organized, and reliable distribution box installations, providing both structural support and a foundation for efficient wiring and heat management.