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3+1 vs 4+0 SPD: Differences, Wiring & Selection Guide

3+1 vs 4+0 SPD wiring and configuration comparison

A 3+1 vs 4+0 SPD comparison often starts with appearance, because both configurations may look almost identical from the outside, especially when they occupy four DIN-rail modules. But electrically, they are not the same. The main difference is the surge…