1. Introduction
The QDX50E Mechanical Type Pressure Switch is designed to monitor hydraulic system pressure and convert it into an electrical signal. This signal can be used to control electromagnetic directional valves, electric motors, or trigger warnings, thereby providing system protection. It operates by opening or closing electrical contacts based on liquid pressure, ensuring precise control and safety in various applications.
Figure 1: Overview of QIDIAN SENSOR Mechanical Pressure Switches
2. Safety Information
- Always disconnect power before installation or maintenance.
- Ensure proper grounding to prevent electrical shock.
- Verify that the pressure range of the switch matches your system requirements.
- Installation should be performed by qualified personnel.
- Do not exceed the maximum pressure rating of the device.
3. Product Components
The QDX50E pressure switch typically consists of the following main parts:
- Stainless Steel Shell: Durable housing for the internal components.
- Hydraulic Interface: Threaded connection for integration into the hydraulic system (e.g., M20*1.5, G1/2, G1/4, NPT1/2, NPT1/4).
- Electrical Connector (DIN43650): Provides electrical connection for output signals.
- Built-in Micro Switch: The sensing element that triggers electrical signals.
- Pressure Adjustment Nut/Screws: For setting the pressure opening and closing points.
Figure 2: QDX50E Pressure Switch with Electrical Connector
Figure 3: Pressure Switch with Detached Connector
4. Technical Specifications
Figure 4: Product Features and Parameters
| Attribute | Specification |
|---|---|
| Model Number | QDX50E |
| Product Name | Pressure Control Switch |
| Item Type | SWITCHES |
| Switch Type | Pressure Switch |
| Measuring Range | 0-400bar / 0-40Mpa (Specific ranges vary by model, e.g., 5-50bar, 10-100bar, 1-16bar, 0.2-2.5bar, 0.8-5bar, 30-300bar, 0.1-2bar, 0-150bar) |
| Output | Normal Open + Normal Close |
| Delaying | 10~20% set value |
| Differential | 3% set value |
| Operating Temperature | -25℃ ~ 85℃ |
| Medium Temperature | -20℃ ~ 85℃ |
| Mechanical Life | 1 million times |
| Protection Class | IP65 |
| Material (Shell) | Stainless Steel |
| Material (Diaphragm) | NBR Nitrile Rubber, EPDM Rubber |
| Material (Hydraulic Interface) | Brass or 304 Stainless Steel |
| Thread Size Options | M20*1.5, G1/2, G1/4, NPT1/2, NPT1/4 |
| Wiring Connector | DIN43650 connector |
| Certification | RoHS, FCC, CE |
| Is Smart Device | No |
| Origin | Mainland China |
5. Installation and Wiring
Before installation, ensure the system is depressurized and power is off.
5.1 Mechanical Installation
- Select the appropriate thread size for your hydraulic system (e.g., M20*1.5, G1/2, G1/4, NPT1/2, NPT1/4).
- Apply thread sealant to the pressure switch's hydraulic interface if necessary.
- Carefully screw the pressure switch into the designated port on your hydraulic system. Do not overtighten.
5.2 Electrical Wiring
The QDX50E pressure switch features a DIN43650 connector. The output includes Normally Open (NO) and Normally Closed (NC) contacts, along with a Common (COM) terminal and a Ground wire.
Figure 5: Wiring and Adjustment Method
- Common Terminal (COM): This is the shared terminal for both NO and NC contacts.
- Normally Closed Terminal (NC): This contact is closed when the pressure is below the set point and opens when the pressure reaches or exceeds the set point.
- Normally Open Terminal (NO): This contact is open when the pressure is below the set point and closes when the pressure reaches or exceeds the set point.
- Ground Wire: Connect to system ground for safety.
Connect the appropriate wires from your control circuit to the corresponding terminals on the DIN43650 connector. Ensure all connections are secure and insulated.
6. Operation and Adjustment
The QDX50E pressure switch allows for adjustment of its pressure set points. A pressure setting value (e.g., 25 bar) indicates the pressure at which the switch will act.
6.1 Adjusting the Pressure Set Point
The pressure switch comes with a pressure point adjustment nut/screws. Follow these steps to adjust the action points:
- Remove Protective Cover: Use a screwdriver to carefully remove the protective Heisman joint (electrical connector cover) to access the adjustment mechanisms.
- Adjust Pressure Opening Point: Refer to Figure 5. Use a hexagonal wrench to adjust the screw that controls the pressure opening point. Turning it clockwise typically increases the set pressure, and counter-clockwise decreases it.
- Adjust Pressure Closing Point: Use a screwdriver to adjust the screw that controls the pressure closing point. This sets the pressure at which the switch resets.
- Verify Setting: Apply pressure to the system and observe a calibrated pressure gauge. Adjust the pressure switch until it acts at your desired pressure value. For example, if you need the switch to act at 25 bar, adjust it while monitoring the system pressure until the switch triggers at 25 bar.
- Reassemble: Once adjusted, replace the protective Heisman joint cover.
Video 1: Product demonstration showing the physical aspects and handling of the pressure switch.
7. Maintenance
- Regular Inspection: Periodically check the pressure switch for any signs of physical damage, corrosion, or leaks.
- Connection Integrity: Ensure all electrical and hydraulic connections remain tight and secure.
- Cleanliness: Keep the exterior of the switch clean and free from excessive dirt or debris.
- Calibration Check: If precise pressure control is critical, periodically verify the switch's set points against a calibrated pressure gauge.
- Diaphragm/Seal Check: While not user-serviceable, be aware that diaphragm or seal failure can lead to leaks or inaccurate readings. If suspected, replace the unit.
8. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Switch does not activate at set pressure | Incorrect pressure setting Faulty wiring Internal switch failure | Re-adjust the pressure set point (Section 6.1) Check wiring connections for continuity and proper terminal assignment Replace the pressure switch |
| Switch activates erratically | System pressure fluctuations Vibration Contamination in hydraulic line | Stabilize system pressure Mount the switch securely to minimize vibration Inspect hydraulic line for debris; consider adding a filter |
| Oil/Water Leakage at connection | Loose hydraulic connection Damaged thread sealant Damaged O-ring/seal | Tighten connection (do not overtighten) Reapply thread sealant Replace the pressure switch if seals are internal and non-replaceable |
| No electrical signal output | No power to circuit Incorrect wiring Internal switch failure | Check power supply Verify wiring against diagram Replace the pressure switch |
9. User Tips
- When ordering, specify the exact pressure range and thread size required for your application to ensure optimal performance.
- For applications involving different media (water, oil), ensure the selected model's diaphragm and hydraulic interface materials are compatible.
- Consider the 'Delaying' and 'Differential' specifications when fine-tuning your system's response to pressure changes.
10. Warranty and Support
This QDX50E pressure switch comes with a 12-month warranty from the date of purchase. The warranty covers manufacturing defects and material faults under normal operating conditions.
For technical support, warranty claims, or any inquiries regarding the product, please contact your seller or the manufacturer directly. Provide your purchase details and model number (QDX50E) for efficient assistance.