Omron D4NL-4DFG-B Safety Door Switch
Omron D4NL-4DFG-B is a 24 VDC guard lock safety door switch with an M20 conduit connection for protective-door interlocking. It uses a solenoid lock with mechanical release, allowing the guard-locking function to be electrically controlled while retaining mechanical release capability. The 2NC + 2NC contact configuration supports separate guard and lock monitoring within a machine safety circuit. A Type 2 low-level coded interlock provides mechanical guard-position detection, while IP67 protection supports industrial installations. Direct opening force is 60 N minimum with 10 mm minimum travel. The D4NL-4DFG-B belongs to the D4NL series within the guard lock safety switch range from Omron industrial safety products.

| Brand | Omron |
| Product Type | Safety Door Switch |
| Model Number | D4NL-4DFG-B |
Omron D4NL-4DFG-B Safety Door Switch - Technical Specifications
| Specification | Value |
|---|---|
| Solenoid voltage/ indicator | Solenoid: 24 VDC, Orange LED: 10 to 115 VAC/VDC |
| Lock and release types | Solenoid lock Mechanical release |
| Contact configuration | 2NC+2NC |
| 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 | 60 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 100 m/s2 min. |
| Ambient operating temperature | −10 to 55°C |
| Ambient operating humidity | 95% max |
| Weight | Approx. 370 g |
The Omron D4NL-4DFG-B Guard Lock Safety Door Switch uses a 24 VDC solenoid lock with mechanical release to control access through protective machine doors. Its 2NC + 2NC contact configuration provides normally closed switching paths for monitoring guard and lock conditions in a machine safety circuit. An M20 conduit connection supports wiring, while a Type 2 low-level coded interlock provides mechanical guard-position detection. The IP67 enclosure supports industrial safety installations where the switch may encounter dust or moisture during machine operation.
Direct opening force is 60 N minimum with 10 mm minimum travel, supporting positive contact separation when the protective guard is operated. The switch supports guard movement from 0.05 to 0.5 m/s. A 24 VDC solenoid controls the locking function, while the orange LED supports 10 to 115 VAC/VDC indication for status visibility. The M20 conduit, 2NC + 2NC contacts and solenoid-lock operating method are useful selection attributes for engineers comparing D4NL guard lock safety switches. These characteristics connect the model directly with protective-door interlocking, machine access control, guard monitoring and safety circuit switching rather than relying on less useful secondary specifications. For an M20 D4NL model using a mechanical lock with solenoid release and additional normally closed contacts, the D4NL-4HFA-B provides a related configuration.


