Automatic Reclosing Relay (DRA)

MERMEC Group automatic reclosing relay is designed to initiate multiple reclosures of a circuit breaker which has been tripped by protective relaying or residual current devices (RCD). It is essentially a timing device, with a heavy-duty stepping switch operating contacts in response to impulses from a solid-state electronic timing circuit.

Protective relays are often interested from unwanted opening due to temporary events as perturbations in the electrical net, impulsive overcurrents of atmosferic and handling origin. In most of the opening actions (95%), a simple switching on of the protective relays solves the problem, because the event, which is responsible of the opening, is disappeared in the meantime.

The reclosing device provides to automatically switch on the protective relay in a sequence of 3 attempts in less than 5 minutes through a quick motor control and a relay system for the system monitoring.

The system is fully automatic and does not require any human operation, neither for the first activation; more, it's possible to drive the motor from a remote position, giving a signal for closing and getting the RCD status information.

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