The operating current rating of the RCCB should be the same as the Main MCB. A custom-built distribution box is necessary when the required power load or connection type exceeds what typical residential or commercial circuits provide. Future solar panels or EV chargers won't require expensive upgrades. The distribution box is just one piece. It receives power from the main electrical supply and divides it into separate circuits, each. Understanding power distribution panels is essential for anyone involved in electrical system design, installation, or maintenance. Whether you're upgrading your home's electrical service, designing a commercial facility, or managing an industrial power system, selecting and sizing the right. The simplest primary distribution system consists of independent feeders with each customer connected to a single feeder.