Schmersal switches and controls promote machine safetyDecember 12, 2014 REDWIRE is news you can use from leading suppliers. Powered by FRASERS.
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Many designers equip their systems with safety controllers because the potential for electrical/mechanical failure is always present — regardless of the reliability of the components in use. Safety controllers detect faults that can compromise safety system operation, thus ensuring system reliability.
Safety control systems require the use of specially designed switches that are resistant to tampering and difficult to override. Mechanically they need to provide positive break contacts and positively linked actuation. Safety circuits need switches with multiple redundant contacts.
Schmersal, with its Canadian headquarters in Brampton, Ont., offers safety relay modules for various safety applications (e.g., for emergency stop and guard door monitoring), as well as centralized programmable safety controllers and decentralized fieldbus systems, including a modular concept for safety function control on small machines.
In addition, the company offers safety-related switches for the position monitoring of guard doors and the non-contact protection of hazardous zones and danger points, as well as safety switching appliances for special applications.
One of Schmersal’s most recent innovations is the PS116 Compact Safety-Rated Limit Switch, an extremely versatile yet compact and robust limit switch for determining the position of movable machine components or machine guards that can be moved laterally or rotated.
For ease of installation, these limit switches are pre-wired with either an M12 connector or a two-metre cable lead on the bottom or side of the housing. Since the housing is symmetrical, the switch can be mounted with the cable or connector to the left or right. The PS116 is available with 10 actuator elements — plungers, roller levers and a rod lever — which are field adjustable, to be set in one of eight positions to meet application requirements.
The PS116 offers two and three contact options, in several configurations. The contacts are either snap action (Z) with optional latching (manual reset), or slow action (T) with overlapping, simultaneous or staggered contacts. All normally closed contacts are positive break, according to IEC 60947-5-1.
In conjunction with an appropriate safety controller, a single position switch can be used up to PLd, while using two can achieve PLe, according to ISO 13849-1.
Contact Schmersal for more information about safety controls and modules.