The Omron D4GS-N4R is a slim safety door switch with 3NC slow-action contacts.
The 3NC contacts mean the switch has three normally-closed channels that open when the guard door is opened. This is the standard configuration for a dual-channel safety input with feedback monitoring — you wire two NC channels to the safety relay and the third can serve as a status signal to a PLC or as a second feedback path. The slow-action (not snap-action) contact mechanism ensures positive opening per EN60947-5-1, so the contacts are mechanically forced open even if they weld shut. Horizontal key insertion means the actuator enters from the side of the switch body, not the front. This suits doors that slide or hinge from the side where a straight-in plunger would not align. The operating speed range of 0.1 to 0.5 m/s and maximum 30 operations per minute define the door cycle — a fast-sliding door or high-frequency access panel may exceed these limits and need a different switch type. The 1 m cable is pre-wired and fixed — no connector option. For panel integration, plan for the cable to reach the first junction box or terminal strip within that length. The slim body saves DIN-rail or panel space compared to standard safety switches, useful in crowded enclosures.