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Compact relay modules for use in hazardous areas

| By Gerald Ondrey

R. Stahl

Two new relay modules have been added to this company’s product range for hazardous areas in Zone 1. The series 9174 and 9177 (photo) relay modules enable a.c. and d.c. loads to be switched using the Ex e and Ex i types of protection. The compact devices are just 12 mm wide, and only require a suitable field enclosure made of plastic or thin-walled stainless steel. The 9177 enables galvanically isolated switching of intrinsically safe (Ex i) and non-intrinsically safe (Ex e) electrical circuits using an electromechanical relay. Any combination of both Ex i and Ex e electrical circuits can be connected to the coil and contact connections. This enables a single relay module to be used in up to four operating modes. The 9174 relay module switches electronically, which makes it suitable for applications with frequent switching operations. — R. Stahl AG, Waldenburg, Germany