Omron D4A-4918N Limit Switch
Omron D4A-4918N is a heavy-duty general-purpose limit switch with a center-neutral rotary actuator and snap-action switching for machine position control. Its DPST-NO/DPST-NC contact arrangement supports multiple control paths, while high inrush capability suits demanding industrial switching. IP67 protection, broad NEMA enclosure ratings, and operation from -40 to 100°C support harsh factory environments and high-cycle machinery. Long mechanical durability makes the switch suitable for machine tools, transfer systems, and automated mechanisms where repeated position feedback is required. The D4A-4918N belongs to the D4A Series within the heavy-duty limit switch range from Omron industrial control products for robust rotary position and travel detection.
| Brand | Omron |
| Product | Limit Switch |
| Model Number | D4A-4918N |
Omron D4A-4918N Limit Switch – Technical Specifications
| Specification | Value |
|---|---|
| Shape Structure | General-purpose Limit switches |
| Ctuator | Rotary action Center-neutral type |
| Contact Form | DPST-NO/DPST-NC |
| Load | General load |
| Inrush Current | NC: 30 A max. NO: 20 A max. |
| Ambient Temperature | Operating: -40 to 100 ℃ |
| Ambient Humidity | 35 to 95% RH (with no icing) |
| Shock Resistance | Destruction: 1,000 m/s 2 max. Malfunction: 300 m/s 2 max. |
| Degree Of Protection | IP67 NEMA Type1, 2, 3, 4, 4X, 5, 6P, 12, 13 |
| Contact Resistance Initial Value | 25 mΩ max. |
| Durability | Electrical: 750,000 operations min. (5 A at 125 VAC) Mechanical: 30 million operations min. |
| Vibration Resistance | Malfunction: 10 to 55 Hz, 1.5 mm double amplitude |
| Operating Mechanism | Snap action |
The Omron D4A-4918N Limit Switch uses a center-neutral rotary actuator with snap-action switching for heavy-duty machine position control. Its DPST-NO/DPST-NC contact arrangement provides multiple normally open and normally closed switching paths from one device, which is useful where a single actuator movement must control several circuit functions. The switch is designed for general loads and supports inrush current up to 30 A on the NC side and 20 A on the NO side. IP67 protection together with multiple NEMA enclosure ratings supports installation in harsh industrial environments where dust, water, and frequent machine operation are expected.
Mechanical durability is specified at 30 million operations minimum, while electrical durability reaches 750,000 operations minimum at 5 A, 125 VAC. Initial contact resistance is 25 mΩ maximum. The D4A-4918N operates from -40 to 100°C with 35 to 95% relative humidity and withstands destructive shock up to 1,000 m/s² and malfunction shock up to 300 m/s². Malfunction vibration resistance covers 10 to 55 Hz at 1.5 mm double amplitude. These characteristics suit high-cycle rotary position and travel detection on heavy machinery. The center-neutral rotary action also helps distinguish this model from plunger and roller-lever limit switch configurations. For another heavy-duty snap-action limit switch with roller-lever actuation, see the D4B-2115N model.
