Omron D4BS-4AFS-NPT Safety Door Switch
Omron D4BS-4AFS-NPT is a 1/2-14NPT safety door switch designed for mechanical monitoring of protective doors and movable machine guards. Its 1-conduit construction provides a defined wiring connection, while the Type 2 low-level coded interlock supports mechanical guard-position detection. The direct opening mechanism provides 19.61 N minimum force with 20 mm minimum travel, and operating speed ranges from 0.1 to 0.5 m/s. IP67 protection supports industrial machine safety installations. The D4BS-4AFS-NPT belongs to the D4BS Series within the safety door interlock switch range from Omron machine safety products, connecting protective access, guard position, direct opening operation and machine safety monitoring.

| Brand | Omron |
| Product Type | Safety Door Switch |
| Model Number | D4BS-4AFS-NPT |
Omron D4BS-4AFS-NPT Safety Door Switch - Technical Specifications
| Specification | Value |
|---|---|
| Type | 1-conduit type |
| Conduit outlet/Connector | 1/2-14NPT |
| Interlock type | Type 2 |
| Coding level | Low level coded |
| Degree of protection | IP67 |
| Operating speed | 0.1 m/s to 0.5 m/s |
| Direct opening force | 19.61 N min |
| Direct opening travel | 20 mm min |
| Contact resistance | 25 mΩ max. |
| Rated insulation voltage (Ui) | 600 V |
| Rated frequency | 50/60 Hz |
| Insulation resistance | 100 MΩ min. |
| Contact gap | 2 × 2 mm min |
| Vibration resistance | Malfunction 10 to 55 Hz, 0.65 mm single amplitude |
| Shock resistance | Destruction: 1,000 m/s2 min. Malfunction: 300 m/s2 min |
| Ambient operating temperature | −40 to 80°C |
| Ambient operating humidity | 95% max |
| Weight | Approx. 285 g |
The Omron D4BS-4AFS-NPT Safety Door Switch uses a 1-conduit construction with a 1/2-14NPT connection for mechanical monitoring of protective machine doors. A Type 2 low-level coded interlock establishes the relationship between the actuator and guard position, while the direct opening mechanism supports positive contact separation when the protective door is operated. The switch provides 19.61 N minimum direct opening force with 20 mm minimum travel and supports operating speeds from 0.1 to 0.5 m/s. IP67 enclosure protection supports industrial machine safety installations where dust or moisture may reach the device. The main semantic relationships are 1/2-14NPT conduit, safety door switching, protective guard detection, direct opening operation and machine access monitoring. These functional attributes provide stronger product context than secondary weight, vibration or electrical resistance specifications. The NPT conduit format is particularly useful for distinguishing this model from D4BS variants using other wiring connections. Its mechanical interlock links movement of the protective guard with the associated machine safety circuit, providing a defined door-position relationship. For another 1/2-14NPT model within the supplied D4BS range with the same core safety door function, the D4BS-45FS-NPT provides a relevant related configuration.


