The D4SLN4VFA is a guard-locking safety-door switch from the Omron D4SL series, with a key-actuated head and 4NC contact configuration. The 4NC (normally-closed) contacts provide the positive-break redundancy required for safety circuits up to PL e / SIL 3 — each NC channel independently confirms the guard is closed and locked before the machine can cycle. Rated switching current is 1.5 A at 120 V AC and 220 mA at 125 V DC — these are the maximum switched loads per contact, not the continuous current. For DC applications, the 220 mA ceiling at 125 V reflects the arc-extinction limit of the slow-action break mechanism; exceeding it risks contact welding on inductive loads like solenoid valves.
Mounting and environmental fit — IP67 and terminal block termination
The switch body measures 39 mm wide by 39 mm deep by 180 mm tall, with a terminal block for field wiring — no connector to source separately. The IP67 rating means the housing and actuator entry withstand dust ingress and temporary immersion to 1 m; suitable for washdown zones in food processing or outdoor conveyor gantries where hose-down cleaning is routine. The head rotates to four directions (4 head directions), so the same switch body can be mounted for left, right, top, or bottom actuator approach without changing the base part. This simplifies panel layout when the guard hinge side is not fixed at design time.
Lifecycle and sourcing — mature production, quoted to order
The D4SL series remains current; if a future replacement appears, it will carry a different order code. For now, the D4SLN4VFA is the part to specify for new designs requiring a guard-locking switch with 4NC contacts and IP67 sealing.