Hager NBN106A 1P B-Curve 6 A Miniature Circuit Breaker

Single-pole B-curve breaker for lighting and small final circuits

The Hager NBN106A is a one-module, single-pole miniature circuit breaker with a B tripping curve and a rated current of 6 A. The B curve trips the magnetic element at a low multiple of rated current, which suits circuits where inrush is small and cable runs are long enough that fault current needs to be detected early, such as lighting groups, control supplies and small socket circuits.

Hager lists a short-circuit breaking capacity of 10 kA under IEC 60898-1 (Icn) and 15 kA ultimate capacity under IEC 60947-2 (Icu), so the same device can be assessed against both household and industrial standards. The body is only 17.5 mm wide, which keeps panel space low when many outgoing ways are needed.

Technical specifications

Temperature behaviour and selection

Like all thermal-magnetic breakers, the NBN106A carries less current as the surrounding air gets hotter. The datasheet tabulates the effective rated current: 6.30 A at 20 °C, 6 A at 30 °C, 5.68 A at 40 °C, 5.35 A at 50 °C, 4.99 A at 60 °C and 4.60 A at 70 °C. Inside a closed panel in a hot climate the air around a breaker is usually well above room temperature, so check the load against the derated value rather than the nameplate 6 A.

Choose the breaker so that the circuit design current is below its effective rating at the real panel temperature, and so that the cable is protected at the same value. If the load has high switching inrush, for example transformers or groups of discharge lamps, confirm that a B curve will not trip nuisance-wise and consider a different curve of the same family.

Installation notes

The device mounts on DIN rail in any orientation. Terminals accept solid conductors up to 35 mm2 and flexible conductors up to 25 mm2 and should be tightened to 2.8 Nm. The biconnect bottom terminal lets a compatible busbar or comb be used for neat multi-way boards.

Documents and quotation

The attached Hager datasheet is the source of every value above. For a quotation, send the order code, the number of poles and the quantity, and state the panel ambient temperature and the type of load so the selection can be checked against the datasheet. See also the circuit breakers category for related protective devices.