The moulded-case circuit-breakers, proposed by OPEN. In particular, OM4 are characterised by an extremely high level of performances with limited overall dimensions, installation simplicity and an increasingly greater guarantee of safety for the operator thanks to their reinforced insulation. OM4 circuit-breakers, thanks to their performances, completeness of protection releases and accessories, can be used for all distribution and sub-distribution application for both AC and DC electrical plants.

Specific characteristics of OM4

The OM4 series is characterised by being a product with a high technological content - the fruit of the most advanced design and simulation tools with excellent performances in minimum overall dimensions.

Thanks to the new technology used for the arcing chambers and the speed of contact opening, the circuit-breakers of the Tmax series guarantee strong limitation of the specific let-through energy and reduction in the peak currents, therefore limiting overheating of the devices and electro-dynamic stresses.

Furthermore, the new Tmax circuit-breakers use a completely common and standardised range of accessories with considerable advantages in terms of reduced stocks as well as flexibility and ease of use. Then within this range there are also the new residual current releases up to 500 A.

Field of application

The moulded-case circuit-breakers are used in industrial and civil low voltage plants with service currents from 1 to 1000 A. They are used in direct and alternating current distribution switchgear, for motor protection (Motor Control Center), generators, capacitors and for end users.