Omron D4NS-4AF Safety Door Switch
Omron D4NS-4AF is an M20 safety door switch designed for protective-door and machine-guard position monitoring. Its 1-conduit construction supports industrial wiring, while the slow-action 1NC/1NO contact configuration provides separate normally closed and normally open switching paths. A Type 2 low-level coded interlock supports mechanical guard-position detection, and the direct opening mechanism provides 10 mm minimum travel. IP67 protection supports machine safety installations where dust or moisture may reach the switch. The D4NS-4AF belongs to the D4NS Series within the industrial safety door switch range from Omron machine safety products, linking protective access, guard position, contact switching and machine safety control.

| Brand | Omron |
| Product Type | Safety Door Switch |
| Model Number | D4NS-4AF |
Omron D4NS-4AF Safety Door Switch - Technical Specifications
| Specification | Value |
|---|---|
| Type | 1-Conduit type |
| Contact configuration | Slow-action, 1NC/1NO |
| Conduit outlet/Connector | M20 |
| Interlock type | Type 2 |
| Coding level | Low level coded |
| Degree of protection | IP67 |
| Operating speed | 0.05 to 0.5 m/s |
| Direct opening force | <Standard type> 60 N min.; <High pull-force type> 80 N min. |
| Direct opening travel | 10 mm min. |
| Contact resistance | 25 mΩ max. |
| Rated insulation voltage (Ui) | 300 V |
| Rated frequency | 50/60 Hz |
| Insulation resistance | 100 MΩ min. |
| Contact gap | 2 × 2 mm min |
| Vibration resistance | Malfunction: 10 to 55 Hz, 0.75 mm single amplitude |
| Shock resistance | Destruction: 1,000 m/s2 min. Malfunction: 300 m/s2 min |
| Ambient operating temperature | −30 to 70°C (with no icing) |
| Ambient operating humidity | 95% max |
| Weight | Approx. 96 g |
The Omron D4NS-4AF Safety Door Switch uses a 1-conduit M20 construction with slow-action 1NC/1NO contacts for protective machine guard monitoring. The normally closed contact provides a safety switching path, while the normally open contact provides an additional switching path within the associated control arrangement. A Type 2 low-level coded interlock mechanically detects protective-door position and connects actuator movement with switch operation. The direct opening mechanism supports positive separation of the safety contact, with 10 mm minimum direct opening travel. Direct opening force is 60 N minimum for standard types and 80 N minimum for high pull-force types. Operating speed ranges from 0.05 to 0.5 m/s, while IP67 enclosure protection supports industrial machine installations where dust or moisture may reach the device. The important semantic relationships are 1NC/1NO contacts, M20 conduit, safety door switching, protective guard detection and direct opening operation. These attributes create useful product context without depending on secondary weight, vibration or resistance values. Within the D4NS family, contact arrangement and conduit type are practical selection criteria for similar safety interlock switches. For an M20 variant requiring 2 normally closed contacts instead of the mixed contact arrangement, the D4NS-4BF provides a relevant related model.


