Omron D4B-4A71N Limit Switch
Omron D4B-4A71N is a D4B-N Series limit switch with a roller plunger, 2NC contacts, and a slow-action operating mechanism for direct machine position detection. The roller plunger suits cams, slides, and moving parts that pass across the sensing point, while the two normally closed contacts support circuits requiring dual NC switching. An M20 conduit entry supports wiring, and operating speed ranges from 1 mm/s to 0.5 m/s. IP67 protection supports installations exposed to dust or moisture, with operation from -40 to 80°C. The D4B-4A71N belongs to the D4B-N Series within the roller plunger limit switch range from Omron industrial control products for machine travel and position sensing.
| Brand | Omron |
| Product | Limit Switch |
| Model Number | D4B-4A71N |
Omron D4B-4A71N Limit Switch – Technical Specifications
| Specification | Value |
|---|---|
| Contact Form | 2NC |
| Shock Resistance | Destruction 1,000 m/s2 min.; Malfunction 300 m/s2 min. |
| Degree Of Protection | IP67 |
| Insulation Resistance | 100 MΩ min. |
| Contact Gap | 2 × 2 mm min. (slow-action) 2 × 0.5 mm min. (snap-action) |
| Actuator | Roller plunger |
| Vibration Resistance | Malfunction 10 to 55 Hz, 0.75 mm single amplitude |
| Operating Mechanism | Slow-action |
| Conduit Size Conduit Openings | M20 |
| Operating Speed | 1 mm/s to 0.5 m/s |
| Operating Frequency | Mechanical 120 operations/minute; Electrical 30 operations/minute |
| Contact Resistance | 25 mΩ max |
| Rated Insulation Voltage Ui | 600 V |
| Rated Frequency | 50/60 Hz |
| Ambient Operating Temperature | –40 to 80°C (with no icing) |
| Ambient Operating Humidity | 95% max |
| Weight | Approx. 250 g |
The Omron D4B-4A71N Limit Switch uses a roller plunger with a slow-action mechanism and 2NC contact configuration for direct machine position detection. The rolling actuator suits cams, slides, and moving parts that pass across the sensing point, while the two normally closed contacts support circuits requiring dual NC switching. Operating speed ranges from 1 mm/s to 0.5 m/s, with up to 120 mechanical and 30 electrical operations per minute. An M20 conduit entry supports wiring, and IP67 protection supports installations exposed to dust or moisture.
Initial contact resistance is 25 mΩ maximum, while insulation resistance is 100 MΩ minimum. Rated insulation voltage is 600 V at 50/60 Hz. The D4B-4A71N operates from -40 to 80°C with relative humidity up to 95%. Destructive shock resistance is at least 1,000 m/s² and malfunction shock resistance is at least 300 m/s². Malfunction vibration resistance covers 10 to 55 Hz at 0.75 mm single amplitude. The slow-action contact gap is specified at 2 × 2 mm minimum. These characteristics suit direct roller-plunger sensing where 2NC contacts and slow-action operation are required together. For a related D4B-N model using a resin roller lever instead of a roller plunger, see the D4B-4A11N model.
