Reclosable residual current circuit breaker makes resetting circuit protection easier

(29/01/2007)

Conventional RCCBs can trip because of temporary transient faults. If the establishment being protected is manned, or if the unit is accessible, it is a simple case of resetting the device to restore power. But, in unmanned applications, or where the device is not easily accessible, the power remains off once the device is actuated.

Merlin Gerin has launched a new reclosable residual current circuit breaker (RED), which brings higher levels of security and more convenience for resetting circuit protection.

The new Merlin Gerin RED range provides three devices to offer secure protection against earth faults, yet automatically reset in the event of a transient.

The first model is the RED that automatically reinstates the supply after checking the insulation of the downstream circuit. If the circuit is faulty, the RCCB reclosing is prevented.

The REDs model performs similarly, but if the circuit is faulty, the RCCD reclosing is prohibited but rechecked after a 15 minute delay. There are two possibilities with this model: the first simply checks the circuit every 15 minutes; the second reports the sequence locally via a five-second intermittent LED and reports remotely via an auxiliary contact. If the fault proves to be a transient, the recloser reinstates the supply.

The REDtest is a more sophisticated model that carries out an automatic electrical and mechanical test of the earth leakage protection every seven days. This test consists of opening and closing the RCCB, during which time the continuity of the downstream installation is guaranteed.

The devices are simple to install and easy to use. For unsupervised installations they avoid costly nuisance trips and yet retain complete circuit safety.

Typical industrial applications that will benefit from the new Merlin Gerin RED range include telecoms, water and gas distribution, computer servers, tunnels, hydroelectric plants and others. In the commercial field, applications will be found in foodstuff preservation (e.g. bars, supermarkets, food stores, ice-cream parlours), as well as automated systems (e.g. alarms, irrigation systems), lighting and heating (e.g. lighted signs or indications, public lighting, heat pumps).

Merlin Gerin is a brand of Schneider Electric.

Related categories:  Circuit breakers MCB, MCCB, ACB   Heating, ventilation, refrigeration   Industrial   Office and commercial   Power