CMTOOL Digital HVAC Manifold Gauge Set

1. Introduction

The CMTOOL Digital HVAC Manifold Gauge Set is designed for the installation, testing, and maintenance of refrigeration equipment such as air conditioners, refrigerators, and cold storage units. This manual provides essential information for safe and effective operation.

1.1 Package Contents

• 1 x Digital Manifold Gauge Unit
• 3 x Standard Test Hoses (1.5m)
• 2 x Temperature Clamps
• 1 x Portable Toolbox
• 1 x User Manual

Image: Components included in the CMTOOL Digital HVAC Manifold Gauge Set.

2. Safety Information

Always observe the following safety precautions to prevent injury or damage to the equipment:

• Wear appropriate personal protective equipment (PPE), including safety glasses and gloves, when handling refrigerants.
• Ensure proper ventilation when working with refrigerants.
• Do not exceed the maximum operating pressure of the hoses (600 PSI / 4.13 MPa). The limit pressure is 3000 PSI.
• Verify that all connections are secure before applying pressure.
• Avoid direct contact with refrigerants, as they can cause frostbite.
• Keep the device away from water and extreme temperatures.
• Ensure the temperature sensor clips are properly connected for accurate readings.

3. Product Features

The CMTOOL Digital HVAC Manifold Gauge Set offers several advanced features for HVAC professionals:

• Dual Pressure and Dual Temperature Measurement: Simultaneously measures two pressures (gauge pressure) and two temperatures.
• Automatic Unit Conversion: Supports automatic conversion for pressure (kPa, MPa, Psi, Bar, InHg) and temperature (Celsius/Fahrenheit).
• High-Precision Data Unit: Features a built-in 32-bit digital processing unit and high-precision data acquisition for stable and accurate readings.
• Refrigerant Database: Contains a built-in database of 89 refrigerants, allowing for direct reading of pressure-evaporation temperature, superheat, and subcooling.
• Vacuum Measurement: Tests the percentage of vacuum.
• Pressure Leak Test: Calculates pressure difference over time to detect refrigerant leaks.
• Durable Construction: Made with high-strength engineering plastics and flexible non-slip silicone for durability and comfortable handling.
• Viewable Window and LCD Display: Allows direct observation of refrigerant charging status and features a 7.5CM×4CM LCD with backlight for clear data reading.

Image: Overview of the digital manifold gauge set's key features.

Image: Comprehensive list of 89 refrigerants supported by the device.

4. Setup

4.1 Component Identification

Image: Labeled diagram of the digital manifold gauge components and dimensions.

1. Clamp-on Temperature Probe Socket
2. LCD Display
3. Function Button
4. Run/Stop Button
5. R+/R- Refrigerant Type Selection Buttons
6. Unit Button
7. Zero Button
8. Backlit Button
9. °C/°F Button
10. Power Button
11. Low Pressure Valve
12. Refrigerant Observation Window
13. 1/4 inch Low Pressure Inlet
14. High Pressure Valve
15. Pressure Release Valve
16. 1/4 inch High Pressure Inlet
17. Refrigerant Inlet / Vacuum Pump Inlet

4.2 Connecting Hoses and Clamps

1. Connect the appropriate test hoses to the low pressure inlet (14), high pressure inlet (17), and refrigerant/vacuum pump inlet (18) on the manifold gauge.
2. Attach the other ends of the hoses to the service ports of the HVAC system.
3. Plug the temperature clamps into the Clamp-on Temperature Probe Sockets (1).
4. Securely attach the temperature clamps to the refrigerant pipes to measure pipe surface temperature.

5. Operating Instructions

5.1 Power On/Off and Backlight

• Press the Power Button (11) to turn the device on or off.
• Press the Backlit Button (9) to activate or deactivate the LCD backlight for improved visibility in low-light conditions.

5.2 Selecting Refrigerant Type

• Use the R+/R- Refrigerant Type Selection Buttons (6) to scroll through the built-in refrigerant database and select the refrigerant being used (e.g., R134A, R410A).

5.3 Pressure and Temperature Measurement

The device displays dual pressure and dual temperature readings simultaneously.

• Ensure hoses and temperature clamps are correctly connected.
• The LCD Display (2) will show T1 and T2 temperatures, along with corresponding pressures.
• Press the Unit Button (7) to cycle through different pressure units (kPa, MPa, Psi, Bar, InHg).
• Press the °C/°F Button (10) to switch between Celsius and Fahrenheit temperature units.

Image: Dual pressure and temperature measurement display.

5.4 Superheat and Subcooling Calculation

The gauge automatically calculates superheat and subcooling based on the selected refrigerant and measured values.

• After selecting the refrigerant, the display will show the calculated superheat (SH) and subcooling (SC) values.

Image: Display showing refrigerant data, superheat, and subcooling.

5.5 Pressure Leak Test

To perform a pressure leak test:

1. Connect the gauge to the system and pressurize it.
2. Press the Function Button (3) to enter the leak test mode.
3. The gauge will record the initial pressure and continuously monitor for changes.
4. The display will show the leak time (HH:MM) and the pressure difference (ΔP) between the initial and instantaneous pressure values.

Image: Pressure leak test display.

5.6 Vacuum Measurement

The device can measure the percentage of vacuum.

• Connect the gauge to the system and initiate the vacuum process.
• The display will show the vacuum percentage.

Image: Technician performing HVAC system service with the gauge.

6. Maintenance

6.1 Cleaning

• Wipe the gauge unit with a soft, damp cloth. Do not use abrasive cleaners or solvents.
• Ensure the temperature clamps and hoses are clean and free of debris after each use.

6.2 Storage

• Store the manifold gauge set in its portable toolbox to protect it from dust and physical damage.
• Keep the device in a dry environment, away from direct sunlight and extreme temperatures.

7. Troubleshooting

7.1 Inaccurate Temperature Readings

• Issue: Temperature readings appear incorrect or unstable.
• Solution: Ensure the temperature sensor clips are properly connected to the probe sockets and securely attached to the refrigerant pipes. A poor connection can lead to inaccurate values.

7.2 No Display or Device Not Powering On

• Issue: The LCD display is blank or the device does not turn on.
• Solution: Check the battery compartment for proper battery installation and charge level. Replace batteries if necessary.

7.3 Pressure Readings are Unstable or Incorrect

• Issue: Pressure readings fluctuate excessively or seem inaccurate.
• Solution: Verify all hose connections are tight and free of leaks. Ensure the correct refrigerant type is selected in the device settings.

8. Specifications

9. Warranty and Support

CMTOOL products are manufactured to high-quality standards. For warranty information, technical support, or service inquiries, please refer to the contact information provided with your purchase or visit the official CMTOOL website. Please retain your proof of purchase for warranty claims.