Product Overview
The WLD3 is a WL series heavy duty limit switch equipped with a top roller plunger actuator. It is used for compact mechanical position detection, stroke limit control, and machine operation feedback in industrial automation equipment. The top roller plunger structure is suitable for applications where a moving mechanical part presses the actuator from the top direction while the roller helps reduce friction during contact.
This page describes model WLD3 only. It is suitable for automation equipment, conveyors, hoist systems, elevators, cranes, machine tools, and other industrial control systems that require a compact roller plunger type limit switch.
Product Display
The WLD3 uses a compact WL series switch body with a top roller plunger actuator. The product structure includes an aluminum alloy shell, actuator head, contact block, terminal section, and conduit connector for wiring.
Key Technical Data
| Item | WLD3 |
|---|---|
| Product type | Heavy duty limit switch |
| Actuator type | Top roller plunger |
| Contact form | Double-circuit limit switch |
| Protection degree | IP66 |
| Operating force | 26.67N max. |
| Release force | 8.92N min. |
| Pre-travel | 1.7mm max. |
| Overtravel | 4mm min. |
| Movement differential | 1mm max. |
| Electrical life | 500,000 operations or above |
Features
- Top roller plunger actuator for compact mechanical position detection.
- Double-circuit limit switch structure for industrial control circuits.
- Aluminum alloy shell construction for mechanical strength.
- Water-proof and oil-proof structure for demanding industrial environments.
- Built-in contact box with double-spring mechanism for long mechanical life.
- IP66 protection degree when properly installed and sealed.
- Suitable for equipment travel control, position detection, and mechanical interlock applications.
- WL series provides multiple actuator configurations; this page focuses on WLD3 only.
Drawing
Outline and Mounting Dimensions
The drawing is used to confirm the WLD3 switch body size, mounting hole position, top roller plunger direction, actuator stroke, and conduit entry location. Before installation, check that the moving mechanical part can press the roller plunger smoothly without side loading or excessive impact.
Contact Form
The WLD3 uses a double-circuit limit switch contact structure for NO and NC control logic. The contacts change state when the top roller plunger is operated by the moving mechanical part.
Select the wiring logic according to the control circuit. For safety-related or fault-detection circuits, NC logic is often preferred, but the final wiring method should follow the machine electrical design.
Ratings
Rated Load
| Rated Voltage | Resistance Load NC | Resistance Load NO | Lamp Load NC | Lamp Load NO | Inductive Load NC | Inductive Load NO | Motor Load NC | Motor Load NO |
|---|---|---|---|---|---|---|---|---|
| 125VAC | 10A | – | 3A | 1.5A | 10A | – | 5A | 2A |
| 250VAC | 5A | – | 2A | 1A | 5A | – | 3A | 1A |
| 480VAC | 3A | – | 1.5A | 0.8A | 3A | – | 1.5A | 0.8A |
| 600VAC | 1A | – | 1A | 0.5A | 1.5A | – | 1A | 0.5A |
| 8VDC | 10A | – | 6A | 3A | 10A | – | 6A | – |
| 14VDC | 10A | – | 6A | 3A | 10A | – | 6A | – |
| 30VDC | 6A | – | 4A | 3A | 6A | – | 4A | – |
| 125VDC | 0.8A | – | 0.2A | 0.2A | 0.8A | – | 0.2A | – |
| 250VDC | 0.4A | – | 0.1A | 0.1A | 0.4A | – | 0.1A | – |
Load Notes
- Surge current: NC 30A under, NO 20A under.
- Inductive load has a power factor of 0.4 minimum for AC and a time constant of 7 ms maximum for DC.
- Lamp load inrush current is approximately 10 times the steady-state current.
- Motor load inrush current is approximately 6 times the steady-state current.
- For inductive, lamp, or motor loads, consider inrush current during circuit design.
Specifications
Electrical
| Item | Specification |
|---|---|
| Contact resistance | 25 mΩ max., initial value |
| Insulation resistance | 100 MΩ min. at 500 VDC |
| Dielectric strength 1 | 1500 VAC, 50/60 Hz for 1 minute between current-carrying and non-current-carrying metal parts |
| Dielectric strength 2 | 1500 VAC, 50/60 Hz for 1 minute between each terminal and ground |
| Electrical life | 500,000 operations or above |
Mechanical
| Item | Specification |
|---|---|
| Operating speed | 1 mm to 1 m/s |
| Operating frequency | Electrical: 30 operations/min |
| Vibration | 10–55 Hz, 1.5 mm double amplitude |
| Shock durability | 1000 m/s², approx. 100G |
| Shock malfunction | 300 m/s², approx. 30G |
Environmental
| Item | Specification |
|---|---|
| Ambient temperature | -20°C to +80°C, with no icing |
| Humidity | <95% RH |
| Protection degree | IP66 |
Operating Characteristics
The following operating characteristics apply to model WLD3 only. The actuator stroke and contact direction should be checked according to the machine structure and the movement of the operating part.
| Parameter | Description | WLD3 |
|---|---|---|
| OF | Operating force, maximum | 26.67N |
| RF | Release force, minimum | 8.92N |
| PT | Pre-travel, maximum | 1.7mm |
| OT | Overtravel, minimum | 4mm |
| MD | Movement differential, maximum | 1mm |
Selection Guide
Actuator and Contact Direction
WLD3 uses a top roller plunger actuator. It is suitable when the machine part presses the actuator from above and slight rolling contact is required. The actuator should not be side-loaded or used as a mechanical stopper.
Electrical Load and Contact Rating
Confirm the circuit voltage, current, load type, and contact logic before selection. For motor, lamp, or inductive loads, select the switch according to inrush current as well as steady-state current.
Stroke and Reset
For WLD3, the pre-travel is 1.7mm maximum and the overtravel is 4mm minimum. The moving part must press the roller plunger reliably and allow the actuator to return fully after operation.
Installation Environment
WLD3 has IP66 protection and is suitable for dusty, oily, and general industrial environments when properly installed. The cable entry and conduit connector should be sealed correctly. Avoid continuous immersion and excessive direct impact.
Replacement Check
Before replacing an existing limit switch with WLD3, check actuator type, mounting dimensions, plunger direction, rated load, operating stroke, conduit size, and wiring logic.