The D4NL1DFABS is a safety door lock switch from Omron's D4NL series, designed to interlock and lock access doors on machinery where a guard must stay closed until hazardous motion stops. It uses a mechanical lock and key actuator, so the door cannot be opened until the lock solenoid is de-energized (or the key is released mechanically). Contact configuration is 4NC — four normally-closed safety contacts wired in series for a dual-channel safety circuit (Cat 4 / PL e per ISO 13849-1 when monitored correctly). The screw terminals accept standard panel wiring, and the IP67 rating means the switch body and actuator withstand washdown environments — food processing, packaging, or any line where hoses are used.
Rated 3 A at 240 V AC and 270 mA at 250 V DC. The AC figure covers most control-circuit loads (relay coils, contactor coils, PLC inputs) in a 120–240 V panel. The DC rating is lower because DC arcs are harder to extinguish — 270 mA at 250 V is typical for DC solenoids or indicator lamps. If your load exceeds these, you'll need an interposing relay. Electrical life is 500,000 cycles at rated load; mechanical life is 1 million cycles. That's a solid service life for a machine running one or two cycles per minute over a decade. The four head directions (top, bottom, left, right) give flexibility in mounting orientation on the guard frame.