Product Overview
The WLD is a heavy duty limit switch equipped with a stainless steel pin plunger actuator. It is used for mechanical position detection, travel-limit control, and stroke feedback in industrial machinery and automation systems. The pin plunger actuator is suitable for applications where a moving part directly presses the plunger in a controlled direction.
This page describes model WLD only. The product is suitable for machine tools, conveyors, elevators, hoists, packaging equipment, material handling systems, and other industrial equipment requiring direct mechanical end-position detection.
Product Display
The WLD uses a heavy duty switch body with a stainless steel pin plunger actuator. The structure includes an aluminum alloy housing, plunger actuator head, terminal cover, sealing components, and conduit section for field wiring.
Key Technical Data
| Item | WLD |
|---|---|
| Product type | Heavy duty limit switch |
| Actuator type | Stainless steel pin plunger |
| Contact structure | Double-circuit contact |
| NO terminal | 3–4 |
| NC terminal | 1–2 |
| Protection degree | IP66 |
| Operating speed | 1 mm to 1 m/s |
| Operating force | 26.67 N max. |
| Release force | 8.92 N min. |
| Pre-travel | 1.7 mm max. |
| Overtravel | 6.4 mm min. |
| Movement differential | 1 mm max. |
| Electrical life | 500,000 operations or above |
Features
- Double-circuit contact structure for NO and NC control logic.
- Stainless steel pin plunger actuator for direct mechanical operation.
- High mechanical strength with aluminum alloy housing.
- Water-proof and oil-proof construction for industrial environments.
- Built-in contact box with double-spring mechanism for stable switching action.
- IP66 protection degree when properly installed and sealed.
- Suitable for machine tools, elevators, hoists, conveyors, and automation equipment.
- Other actuator configurations are available in the WL series for different machine structures. This page focuses on the WLD pin plunger type.
Drawing
Outline and Mounting Dimensions
The drawing is used to confirm the product outline, mounting hole position, plunger direction, actuator travel, conduit position, and installation space of the WLD. Before installation, confirm that the moving mechanical part can press the plunger straight and smoothly within the allowable stroke.
The plunger should not be exposed to side loading or excessive impact. Misalignment, insufficient overtravel allowance, or direct use as a mechanical stopper may affect contact stability and mechanical life.
Contact Form
WLD uses a double-circuit contact structure with normally open and normally closed contacts. The normally open contact uses terminals 3–4 and closes when the actuator is operated. The normally closed contact uses terminals 1–2 and opens when the actuator is operated.
Wiring logic should be selected according to the control circuit. Safety-related circuits often use NC logic, but the final selection should follow the electrical design of the equipment.
Ratings
Rated Load Table
| 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 | 10A | 3A | 1.5A | 10A | 10A | 5A | 2A |
| 250VAC | 5A | 5A | 2A | 1A | 5A | 5A | 3A | 1A |
| 480VAC | 3A | 3A | 1.5A | 0.8A | 3A | 3A | 1.5A | 0.8A |
| 600VAC | 1A | 1A | 1A | 0.5A | 1.5A | 1.5A | 1A | 0.5A |
| 8VDC | 10A | 10A | 6A | 3A | 10A | 10A | 6A | 6A |
| 14VDC | 10A | 10A | 6A | 3A | 10A | 10A | 6A | 6A |
| 30VDC | 6A | 6A | 4A | 3A | 6A | 6A | 4A | 4A |
| 125VDC | 0.8A | 0.8A | 0.2A | 0.2A | 0.8A | 0.8A | 0.2A | 0.2A |
| 250VDC | 0.4A | 0.4A | 0.1A | 0.1A | 0.4A | 0.4A | 0.1A | 0.1A |
Load Type 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, the inrush current should be considered 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 |
| Weight | About 275 g |
Environmental
| Item | Specification |
|---|---|
| Ambient temperature | -20°C to +80°C, with no icing |
| Humidity | <95% RH |
| Degree of protection | IP66 |
Operating Characteristics
The following operating characteristics apply to model WLD only. The mechanical stroke and actuator position should be checked according to the installation direction, plunger stroke, and the moving part of the machine.
| Parameter | Description | WLD |
|---|---|---|
| OF | Operating force, maximum | 26.67 N |
| RF | Release force, minimum | 8.92 N |
| PT | Pre-travel, maximum | 1.7 mm |
| OT | Overtravel, minimum | 6.4 mm |
| MD | Movement differential, maximum | 1 mm |
Selection Guide
Actuator and Motion Direction
WLD uses a pin plunger actuator and should be operated by a moving part that presses the plunger straight in the correct direction. It is suitable for direct end-position detection where the machine stroke is controlled and repeatable.
Electrical Load and Contact Rating
Before selecting WLD, confirm whether the circuit is AC or DC, the operating voltage, current, load type, and whether the control system uses NO or NC logic. For motor, lamp, or inductive loads, select the switch according to the inrush current and not only the steady-state current.
Plunger Stroke and Reset
The plunger stroke should remain within the specified pre-travel and overtravel range. The moving part must press the plunger reliably without side force or impact damage. After actuation, the plunger must return smoothly to its original position.
Installation Environment
WLD has an IP66 protection degree and is suitable for industrial environments with dust, oil mist, and light water exposure. It is not designed for continuous immersion. Avoid direct high-pressure water jet unless additional protection is used. The cable entry must be properly sealed.
Wiring and Contact Logic
The normally open contact uses terminals 3–4, and the normally closed contact uses terminals 1–2. Select the contact logic according to the control circuit. Safety or fault-detection circuits often use NC logic, but the final wiring method must follow the machine electrical design.