Safety limit switch with manual pull-reset for overtravel guarding
The Omron D4N-6D62R is a D4N-R series safety limit switch designed for overtravel detection on elevators, moving tables, and similar guided-motion applications. Its 3NC slow-action contact block provides three normally-closed channels that open on actuation, giving a positive-break safety circuit per the standard for this class. The one-way roller arm lever (horizontal orientation) actuates from a cam or ramp in one direction only, then resets via a manual pull mechanism — no automatic reset, which is intentional for applications where a latched-off state after a trip is the safer response.
Contact and actuator details
The 3NC (slow-action) contacts are rated for the full switching capacity of the D4N-R family. Slow-action means the contacts change state at a speed determined by the actuator movement, not by a snap spring — this gives a defined opening sequence and avoids contact welding on low-energy circuits. The one-way roller arm lever accepts actuation from one direction only; the roller follows a cam profile, and the lever returns to its rest position when the cam withdraws. The manual pull-reset handle on the switch body requires a deliberate pull to reset the contacts after a trip — no automatic return, which prevents a machine restarting without operator intervention.
Mechanical limits and conduit entry
Maximum actuation frequency is 30 operations per minute, and the operating speed range spans 1 mm/s to 0.5 m/s. Below 1 mm/s the slow-action contacts may not achieve a clean break; above 0.5 m/s the mechanical life may be reduced. The G1/2 double conduit entry accepts standard metric or PG cable glands — two entries allow daisy-chaining the safety circuit through the switch without a separate junction box. The switch body is designed for panel or machine-frame mounting with the roller arm positioned to engage the cam at the overtravel limit.