1.1 Function

protection of circuits against short-circuit currents,protection of circuits against overload currents,switch,isolation.

NB1-63H circuit-breakers are used in domestic installation, as well as in commercial and industry electrical distribution systems.

1.2 Selection

Technical data of the network at the point considered:short-circuit current at the circuit-breaker installation point, which must always be less than the breaking capacity of this device,network normal voltage.

Tripping curves:

B curve (3-5In) 

protection for people and big length cables in TN and IT  systems. 

      C curve (5-10In)

protection for resistive and inductive loads with low inrushcurrent.

      D curve(10-14In)

protection for circuits which supply loads with high inrush current at the circuit closing 

(LV/LV transformers, breakdown lamps).