Mastercool 99773-AR HVAC Digital Manifold - Manual (Page 3)

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and the correct vacuum reading to appear. ( 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.)
NOTE: (SEE FIG. A) To disconnect the
vacuum sensor cable be sure to press
the release latch under the connector
cable. Pulling on the cable without
disengaging the latch will cause
damage and is not replaceable under
warranty.
FIG. A
IMPORTANT NOTES FOR SERVICING AC/R SYSTEM
A system that has been opened or one that is found to be excessively low on refrigerant
pressure as a result of a leak, must be fully evacuated by means of recovery/recycling and
deep vacuum. A system that has been evacuated must be repaired, leak tested and
evacuated again before charging.
DIAGNOSING THE SYSTEM PRESSURE AND TEMPERATURE
1. Make sure both valves on the manifold are closed (turn knobs clockwise).
2. Connect the blue and red hose from the low and high side of the manifold to the system.
3. Start the system and allow some time for the true pressure reading on the manifold to
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)
VACUUM CABLE
TO LOW SIDE (BLUE)
TO HIGH SIDE (RED)
TO VACUUM PUMP
CONNECT TO SYSTEM
OR PUMP
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 additional 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