A 3-phase distribution board handles three active conductors — L1, L2, and L3 — plus a neutral and earth (in a four-wire system). It's designed for three-phase power systems, which are the standard for industrial, commercial, and high-demand installations across Australia. (1) Power distribution from the primary main distribution board (distribution cabinet) to secondary distribution boards can be branched; that is, one main distribution board may supply power via multiple branch circuits to several secondary distribution boards. It also provides protection against overloads, short circuits, and earth faults using circuit breakers and protective devices. Many factories and businesses use these boxes to run things like motors, air compressors, and heaters. Big buildings with many floors. These boards, commonly referred to as TPN boards, manage power distribution in a way that maximizes efficiency and ensures protection for your circuits and equipment.
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