Everything You Need to Know About Electrical Distribution Board

  • A distribution board, also known as a panel board or breaker, is an element of an electrical supply system that separates electrical power feeds into secondary circuits, all while providing said circuits with a protective fuse. There are several different types and sizes of electrical distribution boards available on the market, such as surface mounted, flush mounted, or floor standing. The size of these distribution boards will depend on the number of circuits required within the board.

    Whether for a residential, commercial, or industrial building, electrical distribution boards are a crucial part of electrical installations. It controls the incoming power to prevent overloads from occurring. While they are mainly used to distribute the electrical supply throughout the building, there are other electrical distribution boards that are for specific applications, such as for swimming pools, irrigation systems, or ready boards for low-cost housing. Regardless of its application or main purpose, all distribution boards need to be controlled by a switch disconnector, which is often referred to as the main switch.

    The switch disconnector should be mounted either inside or next to the distribution board. If it is the main electrical distribution board, the switch should be labelled “main switch”. If it is the sub-distribution board, the switch should be labelled as “sub-main switch”. Finally, it is important that a danger notice be placed on or near the board with instructions to switch the switch disconnector off in the event of a leakage or inadvertent contact.

    If you are currently in the process of developing a new residential, commercial, or industrial building and need to have an electrical distribution board installed, it is of utmost importance that you ensure that it complies with the requirements of SANS 10142. In addition to this, every item of electrical equipment used in the distribution board should comply with the necessary requirements, some of which will be discussed below.

    For starters, electrical distribution boards should be suitable for the environmental conditions in which they operate. For example, a distribution board for a residential property will be vastly different to one used in an industrial building with unfavourable environments. As such, these boards should also be protected against corrosion, either by specific systems or by using non-corrosive materials.

    Secondly, in terms of the placement of electrical distribution boards, they should not reach 2200mm above the floor if they have to be reached during normal operation, unless there is a switch disconnector that can disconnect it from the supply less than 2200mm above the ground. In terms of residential properties where infants may be able to access the board, no part of the indoor board can be less than 1200mm from the ground, and no part of an outdoor board can be less than 200mm from the ground.

    Finally, electrical distribution boards without any form of protection cannot be mounted in bathrooms, above cooking appliances, within a 1m radius of a tap or valve, or above areas where smaller appliances can be placed below it.