GK-2 CATALOG-HANDBOOK FIFTH EDITION FOR MONITORING & CONTROL OF MACHINE GUARDING SAFETY SYSTEMS USING: . Safety Interlock Switches . Safety Limit Switches . Safety Light Curtains . E-Stop Pushbuttons . Cable-Pull Switches . Two-Hand Controls . Safety Mats . Safety Edges . Signals for Safe Speeds and Standstill Monitoring Safety Controllers Courtesy of Steven Engineering, Inc. - (800) 258-9200 -
[email protected] - www.stevenengineering.com Schmersal Safety Controllers What are Safety Controllers? Safety controllers are connected between machine guarding devices such as keyed interlocks, non-contact sensors, light curtains, etc. and the machine’s stop control elements such as a motor contactor or control relay. These controllers contain redundant, self-checking monitoring circuits and positive-guided relays and/or solid state outputs. Each is designed to detect faults in the safety system’s components and interconnection wiring, and their own internal monitoring circuits and output. Detection of a fault, or of an open machine guard, disables the controller’s output signal(s) facilitating machine stoppage, and/or prevents the restarting of the machine until the fault has been corrected. Units are available for use with guard interlock switches, coded-magnet sensors, safety edges, two-hand controls, light curtains, E-stops and emergency cable-pull switches to satisfy a broad range of application requirements. What are their functions? In addition to detecting open guards and/or actuated safety input devices, safety controllers are capable of detecting the following types of safety system faults: guard monitoring switch/sensor failure, “open-circuit” in interconnection wiring, “short-circuit” in interconnection wiring, “short-to-ground” in interconnection wiring, “cross-short” between channels, welded contact in controlled output device (such as positive-guided motor contactor), failure of safety controller’s positive-guided relay(s), fault in safety system monitoring circuit, and insufficient operating voltage.