MCBs suitable for industrial or building use

Edited by the Engineeringtalk editorial team Feb 9, 2000

Moeller has just introduced two new ranges of miniature circuit breakers specifically developed to provide optimum protection whatever the application.

Moeller has just introduced two new ranges of miniature circuit breakers specifically developed to provide optimum protection whatever the application and wherever it is to be found.

The FAZ and AZ ranges are equally at home providing efficient and reliable protection for cables and control systems in both severe industrial environments and in service installations in buildings.

The FAZ miniature circuit breaker provides a uniform switching capacity of 10kA across its 0.5 to 63A rating range.

A choice of single-, double, triple- and four-pole devices are provided, with the single- and three-pole breakers also available with an additional neutral pole.

For higher current levels and greater short circuit currents, Moeller has introduced the AZ high capacity miniature circuit breaker.

With ratings up to 125A and suitable for fault current levels up to 25kA, the AZ is also offered in single- to four-pole versions.

Rapid disconnection by FAZ and AZ provides effective protection against overloads and short circuits.

Different applications require different tripping characteristics and a variety of device types are available differentiated by the response value of the short-circuit release as laid down by the IEC/EN 60898 standard.

'B' characteristic types trip at short-circuit levels of from 3 to 5 times the rated current.

They are suitable for the protection of lighting and socket outlet circuits.

'C' characteristic units react at 5 to 10 times rated current and are used wherever operational current peaks and other over-currents may occur which must not cause tripping, for example high motor starting currents.

Moeller has also added the 'D' type miniature circuit breaker to its range.

'D' characteristic devices are ideal for -more- applications where high inrush current peaks occur, for example with transformers, motors with severe starting duty or where groups of luminaries are connected downstream.

The short-circuit release of a 'D' type device does not occur until between 10 and 20 times the rated current is achieved, thus ensuring both safety and operational continuity.

The FAZS circuit breaker is designed to protect control circuits having high inrush peaks.

Its high short-circuit release response value lies above the inrush current of a control transformer, thus preventing early tripping.

Tested to IEC/EN 60947-2, the FAZS allows only small overloads of between 5 and 30% to occur.

The FAZR device is ideal for the protection of high impedance conductors and thyristors which can be destroyed by quite small over-currents.

By reacting immediately to over-currents as low as 2 to 3 times rated current the FAZN provides more than adequate protection to these sensitive electronic components.

FAZ miniature circuit breakers meet the IEC/EN 60898 standard while AZ high capacity miniature circuit breakers are built to IEC/EN 60947.