DC power contactors are needed to reliably interrupt the current during shutdown of central inverters in grid connected solar power systems.
The quality of a contactor is decided by how well it tackles electrical arcing at high voltages. Schaltbau DC contactors are true masters in extinguishing the arc.

With decades of experience in railway engineering, Schaltbau has realised sophisticated solutions and developed reliable power contactors for power plants.

The innovative core of the new CT series is the electric arc control technology: in contrast to contactor concepts purely based on electromagnetic blowout, the arcs created at the moment of switching off are ignited in powerful permanent-magnetic blowout fields. Thus the dwell periods in the contact zones are limited to an absolute minimum. This leads to a significant reduction in arc-related burn-up when switching off. The lower degree of wear on the contacts makes it possible to greatly increase maintenance intervals.

The arcs blown out of the contact zones act as wear-free switches in the next phase: the skipping to adjacent arc modulators activates the blowout coils, making switching-off procedures independent of the direction of the current from that moment onwards. In the final phase the arcs pass through an arc chute, are stretched across the divergently arranged modulators and then effectively extinguished in a ceramic chamber. The special design of the extinguishing process reduces the discharge of ionised gases from the arc chute.

The double-interrupting contact system has a symmetrical mirror-image formation. It features both high functionality and reliability, both when subjected to changing polarities and when dealing with critical currents (high voltages, low currents), which are difficult to switch.

The CT contactor concept is flexible and can, for instance, be adapted to suit the needs of the customer with regard to the number of contacts, the design of auxiliary contacts and the connection technology. The product family, which is currently being expanded, comprises a number of various design versions catering to a wide range of uses.

Due to its technical characteristics, its economical advantages, its compactness and versatility, the CT power contactors are simply predestined for use of renewable energy.