A low-voltage distributor, also referred to as sub-distribution board, SDC or sub-distribution board is a distribution system within main boards with large electrical power. From this central location electrical power is distributed over the electrical installation to provide safe usage.

In production facilities low-voltage distributors are usually combined with the MCC switch cabinets for the centralized control of the machine park. These prefabricated switch and distribution boards have to comply with a separate regulation: NEN-EN-IEC 61439. Even though this regulation prescribes requirements regarding design of the distribution system, the engineer still has a lot of possibilities to apply his own ideas on functionality and execution of a distribution system.


The design of a distribution system determines the physical separation of the different current-carrying parts. Apart from the dimensions and flexibility for current use and future adaptations, the design will also determine the safety of electricians while conducting maintenance and extension work.

The engineer ensures compliance with the safety requirements for mechanics. Separate compartments ensure that the live parts are isolated. All outgoing and feeding components can be separated from each other and from the rail system.

Low-voltage distribution boards are connected to the main distribution board with feeding cables or a busbar trunk. The pre-protection and the manner in which feeding cables are laid down, mainly determine the choices of the cable diameter and the cable type.
Therefore, it is of great importance that engineers’ cable calculations determine the correct size of de cable.

The expertise of our specialists ensures safe designs that are in accordance with the customer’s requirements. The engineers of Beemster Electrical Solutions provide the best advice. For more information about design, supply, installation, modification and maintenance, please feel free to contact us without any obligation.

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