What this switch is and what it handles
The Omron D4A1111N is a heavy-duty limit switch from the D4A series, built for position sensing in industrial environments where ingress and mechanical shock are real concerns. Rated IP67, meaning the housing and plunger seal keep out dust and temporary immersion — suitable for washdown zones, outdoor conveyor lines, or food processing areas where a hose-down is routine. The SPDT contact form gives you both N.O. and N.C. circuits in one switch, so you can wire a safety loop and a status signal from the same actuator without an extra relay. AC contact rating is 10 A at 250 V — that's the resistive load curve; for motor or inductive loads, derate per the standard switching category. DC ratings are split by voltage: 10 A at 14 V or 8 V, 6 A at 30 V, then drops to 0.8 A at 125 V and 0.4 A at 250 V. That steep derate above 30 VDC is typical for DC switching — arc extinction is harder, so the switch is limited accordingly.
Build and mounting
Aluminum body, surface-mount with two 0.2 in holes spaced 59 mm vertically and 29 mm horizontally. The plunger actuator is on top, boot-sealed from the factory — no need to add a separate cover in damp environments. Total travel is 0.25 in, which gives a reasonable overtravel margin for cam or dog actuation. Screw terminals inside, so field wiring is straightforward with standard tools. NEMA ratings cover 1, 2, 3, 4X, 5, 6P, 12, and 13 — that's indoor and outdoor, corrosion-resistant (4X), and oil-tight (12/13). The IP67 rating aligns with NEMA 6P for temporary submersion.