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v1.13

Minor Versionm

by StJohn Vuetilovoni

Introduction

Checking the compressor pressure and refilling it with coolant is essential to ensure optimum performance of the temperature management system. It can be done as part of scheduled servicing or as a troubleshooting exercise.

The coolant in the compressor is a common refrigerant gas - R134a (1,1,1,2-Tetrafluoroethane). The gas must be purchased locally because Aeroqual cannot ship gas.

To understand how often you should perform this service activity, click here.

  1. Enter service mode so any fluctuations in the data caused from this activity can be excluded from air quality reports.
    • Enter service mode so any fluctuations in the data caused from this activity can be excluded from air quality reports.

  2. Make sure the monitor has been running for at least 1 hour with the door closed before attempting to refill the compressor.
    • Make sure the monitor has been running for at least 1 hour with the door closed before attempting to refill the compressor.

    • Open the door to the monitor and leave the door open during this process.

    • Find the internal temperature sensor which is plugged into the side wall of the TMS module.

    • Unplug the temperature sensor and replace it with the temporary plug.

    • Leave the temporary plug in for the rest of this procedure.

  3. Unscrew the protective cap from the gas inlet, and put in a safe place because you will need to put it back on later.
    • Unscrew the protective cap from the gas inlet, and put in a safe place because you will need to put it back on later.

  4. Remove the charging cap from the end of the pressure gauge.
    • Remove the charging cap from the end of the pressure gauge.

    • Screw the charging cap from the pressure gauge on to the gas inlet on the compressor.

  5. The compressor requires that gas be added to a specific pressure, not a specific weight, so it's very important to use the pressure gauge provided by Aeroqual when re-filling the compressor with gas.
    • The compressor requires that gas be added to a specific pressure, not a specific weight, so it's very important to use the pressure gauge provided by Aeroqual when re-filling the compressor with gas.

    • Attach the pressure gauge by pushing it into the fitting on the compressor inlet.

    • The gauge will respond SLOWLY.

    • Wait 5 minutes for the gauge to stabilize before continuing with the next step.

  6. Attach one end of the charging hose to the pressure gauge and the other end to the can  or cylinder of R134a. DO NOT open the valve on the can  or cylinder yet.
    • Attach one end of the charging hose to the pressure gauge and the other end to the can or cylinder of R134a.

    • DO NOT open the valve on the can or cylinder yet.

  7. Your target pressure depends on the current temperature of the room or environment where you are performing this exercise.
    • Your target pressure depends on the current temperature of the room or environment where you are performing this exercise.

    • Find out the current ambient temperature, then use the following table to identify your target pressure in PSI.

    • The pressure variation is only a few PSI. It’s important to try to achieve the target pressure point.

    • The risk of under pressurizing is that the monitor won’t be able to control the internal temperature in hot outdoor conditions.

    • The risk of over pressurizing is that during the cooling cycle the monitor will cool too rapidly. This leads to an overshot of the target temperature and unstable sensor readings.

  8. Gently open the valve of your can  or cylinder and watch the pressure gauge increase until just over your desired set point.
    • Gently open the valve of your can or cylinder and watch the pressure gauge increase until just over your desired set point.

    • Shut the valve and wait 3 to 5 minutes for the pressure to stabilize.

    • The gauge might slowly come down again as the gas pressure equilibrates in the cooling system.

    • If the needle drops below your target pressure, repeat the process, each time only letting in a small amount of gas and waiting for the needle to stabilize.

    • Make sure that you read the gauge correctly. The PSI scale is the inside blue scale (the outside scale is bar).

  9. You should not overfill the compressor.  If you overfill by mistake, you can release pressure using the valve on the tee.
    • You should not overfill the compressor. If you overfill by mistake, you can release pressure using the valve on the tee.

    • Unscrew the connection to the valve.

    • Use a pen to press in the valve pin for 2 seconds.

    • Wait 2 to 3 minutes for the pressure to stabilize.

    • Repeat the process until the pressure reaches the target level.

  10. Gently detach the valve connection.
    • Gently detach the valve connection.

    • You will lose a very small amount of gas during this process.

    • Screw the protection cap back on.

    • Replug the internal temperature sensor into the side wall of the TMS module.

Conclusion

For further support, contact Technical Support.

Tanya Taylor

Member since: 02/25/2020

136 Guides authored

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