The Omron D4C1633 is a roller-plunger limit switch with SPDT contacts and momentary action. The roller sits on top, stainless steel, 0.47 in diameter, fixed — no adjustment. Plunger travel is 0.07 in pretravel, 0.19 in total travel, with 0.01 in differential travel before it resets. That tight differential means it'll catch a cam or dog that barely clears the roller, then drop out fast — useful for precision indexing stops. Rated for 5 A at 250 VAC and 4 A at 30 VDC. The SPDT form gives you both N.O. and N.C. in one body. IP67 rating means the body and the boot-sealed actuator survive washdown, rain, and hose-down cleaning. NEMA ratings 3, 4, and 13 back that up for North American spec sheets — dust-tight, rain-tight, oil-tight. Suitable for conveyor lines, packaging machines, and dirty-wet environments where a standard limit switch would corrode or leak.
Mounting and wiring — what to expect on the panel
Surface-mount body with two mounting holes. Body dimensions: 1.57 in wide, 1.92 in tall, 0.62 in deep plus the plunger and roller. Overall height including the roller and plunger is 3.35 in. The plug-in body configuration means the switch mechanism can be swapped without disturbing the wiring — a time-saver when the line's down and you're swapping a failed head. Comes with a 9.8 ft SJT(O) cable attached. That's a hard-wired connection — no separate connector to lose or corrode. Aluminum body keeps it light but tough; the boot is included over the plunger to keep contaminants out of the actuation shaft.
Approved under CCC, CE, CSA, TUV, and UL Listed standards. That covers China, Europe, Canada, and the US — no extra certification work needed for most global equipment. CSA covers Canada. CE covers the EU machinery directive.