What This Switch Head Does
The Omron D4A0010N is a limit switch head from the D4A series, using a push roller plunger actuator at the top. Its maintained action means the switch contacts stay in the actuated position after the plunger is released — it requires a deliberate reset to return to the normal state. This is the opposite of momentary (spring-return) action; use it where a machine state must latch until manually cleared, such as a guard interlock that signals "door open" until an operator resets it.
Rated IP67, so the head and plunger seal against dust ingress and temporary immersion — suitable for washdown zones in food processing or outdoor conveyor lines. The NEMA enclosure rating covers 1, 2, 3, 4X, 5, 6P, 12, and 13, which means it handles indoor dust, outdoor rain, hose-down, and corrosive environments (4X). The stainless steel arm resists corrosion in those same conditions. Temperature range spans -40 °F to 212 °F. Differential travel is 0.02 in.
Approved under CSA and UL Listing, so it is accepted for North American panel builds without additional agency review. The stainless steel arm and IP67 rating make it a common choice for washdown and corrosive environments in food, beverage, and chemical lines.