Mastercool 99663*A HVAC Digital Manifold - Manual (Page 3)

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appear and stabilize.
CHARGING
1. Verify that both valves on the manifold are shut completely.
2. Turn the A/C system and manifold ON.
3. Connect the other end of the yellow hose to Refrigerant Gas supply.
4. Open manifold low side (blue) valve slowly and start charging. (Follow refrigerant
manufacturer’s instructions for proper dispensing. Use an electronic scale for accurate
charging (Mastercool #98210-A)
5. When charging is finished, close the valve on the tank and allow some time for the
refrigerant to be evacuated from the hoses and manifold.
6. Close the low side valve and disconnect the hose(s) from the system.
VACUUM GAUGE OPERATION (SEE FIG.B)
• Press the POWER button to turn the unit ON. Allow 10 seconds for the unit to initialize.
• Close both valves.
• Connect the high side and low side hoses to the system and the yellow hose to the
vacuum pump.
• Connect the vacuum cable to the manifold. Connect the other end of the vacuum gauge
to the system. (An additonal TEE fitting (Mastercool #99333) or an isolation valve may be
required.)
Press the
VACUUM button and select the desired unit.
Press ENTER to confirm.
• Start the vacuum pump and open both valves. The vacuum countdown will start
from atmospheric pressure 00000. Depending on the size of the system, the lines on
the LCD display will disappear one by one. Once all lines have disappeared, the
numerical reading will appear on the LCD. The numbers descend from 25000 MICRONS
or corresponding units.
NOTE: The unit will shut down after 15 minutes automatically. Press the
POWER button
again. Allow 30-45 seconds for initializing and the correct vacuum reading to appear.
Once the target vacuum is reached, close the low side valve and disconnect the vacuum
gauge port from the manifold. Press the
POWER button to turn the unit off. (If pressure,
temperature or deep vacuum is being used for an extended period of time turn the
unit off and turn back on again when reading is required.)
WARNING!! Never stop the vacuum pump unless the vacuum
gauge is disconnected. Failure to do so may cause oil to enter
the sensor chamber.
VACUUM LEAK TEST
When checking a system for leaks under high vacuum (less than 1000 microns), connect
the vacuum gauge directly to the system. If additional connections are required use cop-
per tubing (do not use rubber hoses) and high vacuum shut-off valves. Standard hoses
and manifold gauge set shut-off valves may have a small amount of leakage under high
vacuum. When initiating a high vacuum test, the vacuum gauge reading may “drift” higher
until the system has equalized. After this short stabilization period (5 minutes) the vacuum
reading should hold steady. An upward “drift” of the vacuum gauge reading may indicate a
leaking system.
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VACUUM CABLE
TO LOW SIDE (BLUE)
TO HIGH SIDE (RED)
TO VACUUM PUMP
CONNECT TO SYSTEM
OR PUMP
FIG. B
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