Omron D4NS-4DF Safety Door Switch
Omron D4NS-4DF is a 3NC safety door switch designed to monitor protective doors and movable machine guards. Its slow-action 3NC contact configuration provides 3 normally closed switching paths for safety circuit monitoring, while the M20 conduit supports industrial wiring. A Type 2 low-level coded interlock provides mechanical guard-position detection, and the direct opening mechanism supports positive contact separation with 10 mm minimum travel. IP67 protection supports use around industrial machinery where dust or moisture may be present. The D4NS-4DF belongs to the D4NS Series within the safety door switch range from Omron machine safety products, connecting guard detection with machine safety control.

| Brand | Omron |
| Product Type | Safety Door Switch |
| Model Number | D4NS-4DF |
Omron D4NS-4DF Safety Door Switch - Technical Specifications
| Specification | Value |
|---|---|
| Type | 1-Conduit type |
| Contact configuration | Slow-action,3NC |
| 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-4DF Safety Door Switch uses slow-action 3NC contacts for protective machine guard monitoring. Its 3 normally closed contacts provide multiple safety switching paths, making the contact configuration a key distinguishing feature within the D4NS Series. The 1-conduit construction uses an M20 connection for machine wiring, while the Type 2 low-level coded interlock provides mechanical guard-position detection. A direct opening mechanism supports positive contact separation when the protective door moves from its monitored position. The switch provides 60 N minimum direct opening force for standard types and 80 N minimum for high pull-force types, together with 10 mm minimum direct opening travel. IP67 protection supports installation around industrial machinery where dust or moisture may reach the switch. These characteristics connect the D4NS-4DF with safety door switches, machine guards, safety interlocks, direct opening contacts and protective access monitoring. For product selection, its 3NC contact arrangement and M20 conduit are more useful differentiators than secondary electrical or environmental specifications. The switch therefore provides a clear relationship between protective-door movement and the machine safety circuit through mechanical interlocking and normally closed contact monitoring. For another M20 D4NS safety door switch using a different slow-action contact arrangement, the D4NS-4FF provides a relevant related model.


