CMTOOL Digital HVAC Gauges Set User Manual

1. Introduction

The CMTOOL Digital HVAC Gauges Set is a professional tool designed for comprehensive HVAC system diagnostics and maintenance. It features a 92-refrigerant database, precise pressure and vacuum testing capabilities, and an intuitive digital display. This manual provides detailed instructions for setup, operation, and maintenance to ensure optimal performance and longevity of your device.

Figure 1: CMTOOL Digital HVAC Gauges Set and included accessories.

2. Product Features

• 92 Refrigerants & 5 Pressure Units: Built-in database for various maintenance occasions with automatic unit conversion.
• Double Pressure Test: Simultaneously measures low-pressure and high-pressure pipelines (0-6000Kpa range, 10000Kpa overload limit).
• Temperature Calculation: Automatically calculates evaporation and condensation temperature.
• Pressure Leak Test: Records initial and instantaneous pressure values, calculates pressure difference, and displays test time.
• Refrigerant Filling & Vacuum Operation: Facilitates refrigerant addition and vacuuming with clear indicators.
• HD Screen Display & Power Display: Backlit digital screen for clear data reading in low light, with battery power indicator.

Figure 2: Overview of the CMTOOL Digital Manifold Gauge Set's key features.

3. What's in the Box

Upon opening the package, please verify that all the following components are present:

• CMTOOL Digital HVAC Gauge Set
• 3 Hoses (Red, Yellow, Blue)
• R134A Quick Connectors
• Valve Core Remover
• Universal Can Tap
• Portable Suitcase
• 3 x 1.5V AAA Batteries
• Refrigerant Hose Seal Accessories
• English User Manual

Figure 3: All components included in the CMTOOL Digital HVAC Gauges Set.

4. Setup

4.1 Battery Installation

The digital manifold gauge is powered by 3 x 1.5V AAA batteries. Locate the battery compartment on the back of the unit, open it, insert the batteries according to the polarity markings, and close the compartment securely.

Figure 4: Battery compartment and installation process.

4.2 Initial Connection

Before operation, familiarize yourself with the gauge's interface and connection points:

• 2.4-inch Digital HD Screen: Displays all measurement data.
• ON/OFF Button: Short press to power on, long press to power off. Short press to turn on/off the backlight.
• FN/ZERO Button: Long press to zero pressure reading. Short press to switch function mode.
• UNIT/°C/°F Button: Short press to switch pressure unit. Long press to switch temperature unit.
• Up/Down Arrows: Short press to switch refrigerant type. Short press to run/stop air tightness test.
• Low Pressure Valve (Blue): Controls the low-pressure line.
• High Pressure Valve (Red): Controls the high-pressure line.
• Visual Filling Window: Allows observation of refrigerant flow.
• 1/4 inch Low Pressure Inlet (I): Connects to the blue hose.
• Refrigerant Inlet/Vacuum Pump Inlet (J): Connects to the yellow hose.
• 1/4 inch High Pressure Inlet (K): Connects to the red hose.
• Foldable Hook (L): For convenient hanging during use.

Figure 5: Product icon and description of components.

5. Operating Instructions

The CMTOOL Digital HVAC Gauges Set supports three primary operating modes: Refrigerant Filling and Pressure Inspection, Vacuum Operation, and Pressure Leak Test. Ensure all connections are secure before beginning any operation.

Figure 6: Three main operating modes of the digital manifold gauge.

5.1 Vacuum Operation

This mode is used to evacuate air and moisture from the HVAC system before charging with refrigerant.

1. Connect the yellow hose from the gauge to the vacuum pump.
2. Connect the blue hose to the low-pressure service port of the HVAC system and the red hose to the high-pressure service port.
3. Ensure both the blue (LOW) and red (HIGH) valves on the manifold gauge are closed.
4. Turn on the vacuum pump.
5. Open the blue (LOW) and red (HIGH) valves on the manifold gauge to begin evacuation.
6. Monitor the "VAC" percentage and pressure reading on the digital display. Vacuuming is complete when the vacuum degree reaches approximately 80%-90% and remains stable without further changes.
7. Once vacuuming is complete, close both the blue (LOW) and red (HIGH) valves on the manifold gauge before turning off the vacuum pump.

Figure 7: Digital display showing vacuum percentage and pressure during vacuum operation.

5.2 Refrigerant Filling and Pressure Test

This mode allows for adding refrigerant to the system and monitoring pressure levels.

1. Ensure the blue (LOW) and red (HIGH) valves on the manifold gauge are closed.
2. Connect the yellow hose to the refrigerant can via the universal can tap.
3. Connect the blue hose to the low-pressure service port and the red hose to the high-pressure service port of the HVAC system.
4. Open the valve on the refrigerant can.
5. Slowly open the blue (LOW) valve on the manifold gauge to allow refrigerant to enter the system. Monitor the pressure readings on the display.
6. Once the desired pressure is reached, close the blue (LOW) valve and the valve on the refrigerant can.
7. Observe the LP (Low Pressure) and HP (High Pressure) readings, along with the calculated evaporation (EV) and condensation (CO) temperatures.

Figure 8: Display showing pressure and calculated temperature units.

5.3 Pressure Leak Test

This test helps identify leaks in the HVAC system by monitoring pressure changes over time.

1. Ensure the system is charged to the desired pressure.
2. Close both the blue (LOW) and red (HIGH) valves on the manifold gauge.
3. Press the "FN/ZERO" button to switch to the pressure leak test mode. The display will show "Time", "ΔP" (pressure difference), "Start Pressure", and "Current Pressure".
4. Press the play button (usually indicated by an arrow on the screen or a specific button) to start the leak test timer.
5. Monitor the "ΔP" value. A significant change indicates a leak. The test time is displayed in "HH:MM" format.
6. Press the stop button to end the test.

Figure 9: Pressure Leak Test display showing initial pressure, current pressure, and pressure difference over time.

6. Specifications

Figure 10: List of 92 refrigerants supported by the device.

7. Maintenance

Proper maintenance ensures the longevity and accuracy of your CMTOOL Digital HVAC Gauges Set.

• Cleaning: Wipe the unit with a soft, dry cloth. Do not use abrasive cleaners or solvents.
• Storage: Store the gauge set in its portable suitcase in a cool, dry place away from direct sunlight and extreme temperatures.
• Battery Replacement: Replace batteries promptly when the low battery indicator appears on the screen to prevent data loss or malfunction.
• Hose Inspection: Regularly inspect hoses for cracks, leaks, or damage. Replace if necessary to maintain system integrity.
• Valve Core Maintenance: Use the included valve core remover for any necessary maintenance on valve cores.

8. Troubleshooting

If you encounter issues with your digital HVAC gauge set, refer to the following common troubleshooting steps:

9. Warranty and Support

For warranty information and technical support, please refer to the warranty card included in your product packaging or visit the official CMTOOL website. You may also contact CMTOOL customer service directly for assistance with product operation, troubleshooting, or replacement parts.

CMTOOL Store: Visit the CMTOOL Store on Amazon