LEFOO LF58 Dual Pressure Control Switch Instruction Manual

1. Introduction

The LEFOO LF58 Dual Pressure Control Switch is designed for precise pressure regulation in various systems. It is commonly used with fluorinated refrigerants to control compressor pressure in refrigeration systems. Additionally, it can be applied in air, water, and oil systems. This device offers two pressure adjustment points within a single switch, ensuring reliable operation through its internal micro switch mechanism. A standard mounting bracket is included for installation.

2. Safety Information

Please read all instructions carefully before installation and operation. Failure to follow these instructions may result in equipment damage, personal injury, or death.

• Ensure power is disconnected before performing any installation, wiring, or maintenance.
• Installation and wiring should only be performed by qualified personnel in accordance with local and national electrical codes.
• Verify that the pressure ranges of the control switch are suitable for your application.
• Do not exceed the maximum rated pressure or temperature for the device.
• Protect the device from physical damage and extreme environmental conditions.

3. Product Overview

The LEFOO LF58 is a dual pressure control switch designed to monitor and regulate both low and high pressure within a system. It features a robust design with an IP54 international protection rating, making it suitable for various industrial environments.

Figure 3.1: Top-front view of the LEFOO LF58 Dual Pressure Control Switch, showing the pressure ports and adjustment covers.

Figure 3.2: Bottom view of the LEFOO LF58 Dual Pressure Control Switch, highlighting the two 7/16-20UNF pressure connection ports.

4. Setup and Installation

4.1 Mounting

The LF58 comes with a standard mounting bracket for secure installation. Choose a location that is easily accessible for adjustments and maintenance, and protected from excessive vibration or direct exposure to harsh elements.

Figure 4.1: The LEFOO LF58 unit shown alongside its included mounting bracket.

Figure 4.2: Exploded view of the LEFOO LF58 components, including the main unit, mounting bracket, and attachment screws.

4.2 Pressure Connections

Connect the pressure lines to the 7/16-20UNF ports located at the bottom of the unit. Ensure all connections are tight and leak-free, especially when dealing with refrigerants or high-pressure fluids.

Figure 4.3: Detailed view of one of the 7/16-20UNF pressure connection ports.

4.3 Electrical Wiring

The LF58 utilizes an SPDT (Single Pole Double Throw) contact arrangement. Refer to the wiring diagram provided with your specific unit for correct electrical connections. Ensure all wiring complies with local electrical codes and safety standards.

The operating mode is ON-OFF, meaning the switch will open or close contacts based on the set pressure thresholds.

5. Operating Instructions

The LF58 allows for independent adjustment of low and high pressure set points. The factory settings are typically 58 PSI ON / 29 PSI OFF for low pressure and 290 PSI ON / 217 PSI OFF for high pressure. These can be adjusted to suit your system's requirements.

Figure 5.1: Top view of the control switch, indicating the "RANGE" and "DIFF" (differential) adjustments for low pressure, and "CUT OUT" for high pressure.

5.1 Adjusting Low Pressure

To adjust the low pressure cut-in and cut-out points, locate the "RANGE" and "DIFF" (differential) adjustment screws under the protective cover. The "RANGE" setting determines the primary low pressure set point, while the "DIFF" setting adjusts the pressure difference between the cut-in and cut-out points.

5.2 Adjusting High Pressure

The high pressure cut-out point is adjusted using the "CUT OUT" screw, also located under a protective cover. This setting determines the maximum allowable pressure before the switch activates to protect the system.

Note: Always make small adjustments and monitor system pressure to ensure desired operation. Consult a qualified technician if you are unsure about pressure settings.

6. Maintenance

Regular maintenance ensures the longevity and reliable operation of your LEFOO LF58 Dual Pressure Control Switch.

• Inspection: Periodically inspect the unit for any signs of physical damage, corrosion, or loose connections.
• Cleaning: Keep the exterior of the unit clean and free from dust and debris. Do not use abrasive cleaners or solvents.
• Pressure Connections: Check pressure connections for leaks and ensure they remain securely fastened.
• Electrical Connections: Verify that all electrical wiring is secure and free from wear or damage.

For any internal maintenance or repairs, it is recommended to consult a qualified service technician.

7. Troubleshooting

If you encounter issues with your LEFOO LF58 Dual Pressure Control Switch, consider the following common troubleshooting steps:

• No Response:
  • Check if the power supply to the control circuit is active.
  • Verify all electrical connections are secure and correctly wired.
  • Ensure the pressure lines are properly connected and not blocked.
• Incorrect Switching:
  • Re-check the low and high pressure settings ("RANGE", "DIFF", "CUT OUT") to ensure they match your system requirements.
  • Confirm that the system pressure is within the operational range of the switch.
  • Inspect for any debris or blockages in the pressure sensing lines.
• Leaks:
  • Tighten all pressure connections. If leaks persist, replace seals or fittings as necessary.

If the problem persists after performing these steps, contact customer support or a qualified technician.

8. Specifications

Figure 8.1: Dimensional drawing of the LEFOO LF58, with measurements provided in millimeters.

9. Support and Contact

For any questions regarding the LEFOO LF58 Dual Pressure Control Switch, please contact our customer support. We aim to respond to all inquiries within 24 hours.

Please refer to the retailer's website or your purchase documentation for specific contact details.