The positioning rails, mounted on the interior side walls of the circuit breaker compartment, capture and align the metal rollers on the circuit breaker to guide the circuit breaker during transport into and out of the connected position. Always put safety first and turn off all power before you begin. With careful steps, you can handle this task even if you do not have much. In this guide, we'll break down everything you need to know to install a distribution box correctly and confidently. Choose the right box based on environment (indoor/outdoor), load capacity, and durability. Check for proper IP/NEMA ratings and material quality. The thermoplastic polyolefin wheels allow for the dedicated metal. Mounting Location: DIN Power Modules (DPMs) will hum slightly and internal relays will click while in use. Mount in a location where such noise is acceptable. Electric Shock. DIN rails provide a convenient way to connect a large variety of electrical components in a small space.