Perfectaire 1PAMSH18-MZO2-16, Service Manual

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and block capillary tubing.
●
Water when mixed with the refrigerant and oil
will create an acid that will damage the motor
windings and components.
Therefore, the indoor units and the pipes between
indoor and outdoor units must be leak tested and
evacuated to remove gas and moisture from the
system.
Gas leak check (Soap water method):
Apply soap water or a liquid neutral detergent on
the indoor unit connections or outdoor unit
connections with a soft brush to check for
leakage of the connecting points of the piping. If
bubbles come out, the pipes have leakage.
1. Air purging with vacuum pump
1. Completely tighten the flare nuts of the indoor
and outdoor units, confirm that both the 2-way
and 3-way valves are set to the front seated.
2. Connect the low pressure gauge to the 3 way
service valve access port.
3. Connect the middle hose of the gauge
manifold (usually yellow) to the vacuum pump.
4. Fully open the handle for the low pressure
gauge.
5. Start the vacuum pump and operate
according to manufacture spec's.
6.
Perform an evacuation for a minimum of 30
minutes and check that the low pressure
(compound) gauge indicates a vacuum of
29.9 in/hg (500 microns). A vacuum gauge
should be used if available. If the proper
vacuum cannot be achieved the vacuum
pump should be run for an additional 20
minutes. If after the additional 20 minutes the
vacuum still cannot be achieved there is a
leak in the system and must be located and
repaired. Follow the leak checking procedure
as mentioned before. If the vacuum is
achieved, close the low pressure gauge
handle off and shut the vacuum pump off.
Recheck the reading after 10 minutes, the
vacuum may change slightly, this is normal.
7. The system is now dry and free of
contaminates, refrigerant pressure should
now be added to the system from a source
other than the system before opening the 2
way and 3 way valves for system operation.
8. The 2 way and 3 way valve can now be
opened for the system operation.
2. Adding refrigerant if the pipe length
exceeds chargeless pipe length
Procedure:
1) Connect the low pressure gauge from the
gauge manifold set to the 3 way service valve
(this is the blue hose on most sets).
2)
Connect the middle hose from the manifold set
to the refrigerant container (this is the yellow line
on most sets). With refrigerant 410A the container
must be inverted (upside down) when adding the
refrigerant. Note that the 2 way and 3 way valves
must be in the open position.
3) The air in the gauge hoses needs to be purged
out. use the pressure from the system to purge
the low side line, loosen the connection on the
manifold for a second, next open the to valve on
the refrigerant container to pressurize the line,
now loosen that hose at the manifold for a second
and purge that line.
4) Set the refrigerant container on an electronic
charging scale and record the weight or zero the
scale depending on the scale used. Next
determine the refrigerant charge to be added.
5) Start the unit in the cooling mode and lower
the set point so the unit won’t shut off during the
charging procedure.