CB
Circuit Breaker (MCB)
BS EN 60898 devices with thermal (overload) and magnetic (short-circuit) trips.
Types
Type B trips instantaneously at 3–5 × In (domestic). Type C at 5–10 × In (inductive loads). Type D at 10–20 × In (high inrush).
Selection
Choose In ≥ Ib and ≤ Iz. Check the maximum Zs from Table 41.3 so the device disconnects within 0.4 s on final circuits up to 63 A (TN).
Key regulations
411.3.2Table 41.3533