A clear decision rule for choosing 3-pole or 4-pole MCCBs based on TN-S, TN-C-S, TT, and IT earthing systems, neutral protection needs, and harmonic loading.

A technical breakdown of MCB pole configurations 1P, 2P, 3P, 4P and 1P+N, covering neutral switching, module width, and TN/TT earthing-system fit for panel b...