Omron VB-3251 Limit Switch
Omron VB-3251 is a multiple limit switch with three roller plungers for detecting several mechanical positions from one compact housing. Each actuator uses a 6.8 mm roller for smooth contact with moving parts, while the no-flange design supports compact mounting and four cable-entry directions provide flexible wiring access. Operating speed ranges from 0.1 mm/s to 0.5 m/s, with 5 million minimum mechanical operations and IP67 protection. The VB-3251 belongs to the VB Series within the multi-point roller plunger switch range from Omron automation products for sequence control, indexing, and position detection where three sensing points are required in compact handling equipment.
| Brand | Omron |
| Product | Limit Switch |
| Model Number | VB-3251 |
Omron VB-3251 Limit Switch – Technical Specifications
| Specification | Value |
|---|---|
| Number Of Plungers | 3 plungers |
| Shape Of Box | Without flange |
| Conduit | Four |
| Ambient Temperature | –10°C to 80°C (with no icing) |
| Ambient Humidity | 35% to 95% |
| Shock Resistance | Destruction: 1,000 m/s2 min. Malfunction: 200 m/s2 min. |
| Degree Of Protection | IP67 |
| Durability | Mechanical: 5,000,000 operations min. Electrical: 300,000 operations min. (10 A at 250 VAC, resistive load) |
| Insulation Resistance | 100 MΩ min. (at 500 VDC) |
| Actuator | Roller plunger (with a 6.8-dia. roller) |
| Vibration Resistance | Malfunction: 10 to 55 Hz, 1.5-mm double amplitude |
| Operating Speed | 0.1 mm to 0.5 m/s |
| Operating Frequency | Mechanical: 120 operations min. Electrical: 30 operations min. |
| Contact Resistance | 15 mΩ max. (initial value) |
| Rated Insulation Voltage Ui | 300 VAC |
| Rated Frequency | 50/60 Hz (AC) |
| Weight | Approx. 580 g |
The Omron VB-3251 Limit Switch uses three roller plungers, each with a 6.8 mm roller, for detecting several mechanical positions from one housing. The rolling actuators provide smooth contact with moving parts, while the no-flange construction supports compact installation. Four cable-entry directions allow wiring to approach from different sides, which can simplify routing in constrained layouts. Operating speed ranges from 0.1 mm/s to 0.5 m/s, with up to 120 mechanical and 30 electrical operations per minute. IP67 protection supports use around dust, water, or oil, while operation extends from -10 to 80°C.
Mechanical durability is specified at 5 million operations minimum, while electrical durability reaches 300,000 operations minimum at 10 A, 250 VAC resistive load. Initial contact resistance is 15 mΩ maximum, and insulation resistance is 100 MΩ minimum at 500 VDC. The VB-3251 withstands destructive shock of at least 1,000 m/s² and malfunction shock of at least 200 m/s². Malfunction vibration resistance covers 10 to 55 Hz at 1.5 mm double amplitude. These characteristics suit three-point sequence and position sensing where no-flange mounting and multiple wiring directions are useful. The four-entry layout is useful when cable routing direction must be selected during installation. For a related three-roller-plunger VB model with two side cable entries, see the VB-3241 model.
