Evacuation After Servicing The Outdoor Unit Refrigeration Circuit - Pioneer YN020GMFI22M2D Service Manual

19. Open the low pressure valve on the gauge
manifold set to start charging the unit with liquid
refrigerant for the remaining amount. Please
remember to nurse the refrigerant in slowly by
controlling the low pressure valve at the Low side
of your gauge manifold (open for 3 seconds and
close for 10 seconds). Keep track of the refrigerant
being added into the system until the entire
intended volume is charged. (do not overcharge
the system).
20. The correct charge has been added to the system
close the low pressure valve on the gauge manifold
set and record the operating pressure. The system
is now charged and the unit can be shut off. Close
the valve on the refrigerant container and
disconnect the hose from the manifold set, also
disconnect the hose from the 3 way valve and
replace and torque all caps.
21. Be sure to use a torque wrench to tighten the
service port cap to a torque 18N·m (13.27 ft·lbs).
Always leak check after servicing the refrigerant
system.
5.6 Procedure to remove, replace or service
the refrigeration circuit of an indoor unit by
Pumping down the system (isolating the
refrigerant charge in the condensing unit):
Procedure:
1. With all indoor units are running in cooling mode
and their controllers are set to a low setting,
remove all brass dust caps from the 3-way (Gas)
and 2-way (Liquid) valves of the circuit of the indoor
unit that is to be removed.
2. Assure the Low and High side valves of your gauge
manifold set are both closed. Attach the low
pressure hose of the manifold gauge to the 3-way
(Gas) service valve port of that circuit. Purge the
air from that hose by loosening the hose where it
connects to the gauge manifold for a second. Be
sure to record the operating pressure, you will
need to know this when you complete the service
on the indoor unit and restart the system. Now get
prepared to close both 3-way (Gas) and 2-way
(Liquid) valves on the unit. Also be prepared to shut
the power off to the outdoor unit entirely.
3. While the system is running, first close the 2-way
(Liquid) valve entirely and monitor the low pressure
gauge. The pressure will start to drop quickly.
4. Keep operating the unit in the cooling mode until
pressure reading on the low pressure gauge of the
manifold drops to zero. At this moment, quickly
close the 3-way (Gas) valve and then immediately
disconnect the power to the outdoor unit. Running
the compressor in a vacuum for a long time could
damage the motor windings. Note that units with
extended lines and additional refrigerant charge
may not be able to pump down the line entirely.
This is because the outdoor unit can only store a
certain amount of refrigerant and this is normal (the
amperage of the compressor will have to be
monitored in this case). There may be little
pressure left in the system. This is normal. The
indoor unit is now ready to be removed and
serviced.
5. Remember to evacuate / vacuum the circuit after
the indoor unit is reinstalled as per the procedures
covered above entirely. Check for leaks as stated
above for new installations. Open both 3-way (Gas)
and 2-way (Liquid) valves to release the refrigerant
to the serviced circuit. Test for leaks again and
proper operation. If you notice less pressure
reading than recorded before the removal of the
indoor unit, top off with a little additional refrigerant.
5.7 Evacuation after servicing the outdoor
unit refrigeration circuit
SEE PARAGRAPH 5.5 AND FOLLOW THE SAME
PROCEDURE.
NOTE: Frequent servicing and attachment of hoses
to the service ports, may damage the seals of the
Schrader valves inside of those service ports. Always
check for leaks at each of the service ports after the
gauge manifold hose is disconnected from that port.
If you notice a leak at the service port, the Schrader
valve core will need to be replaced. There is a
special tool that can be used to replace the Schrader
valve core without losing refrigerant. Refer this to
your service company.
Refrigerant is Toxic and can create serious frost
bites on your skin. Always assure to wear safety
gear to protect your skin and eyes. Seek medical
assistance in case of accidents.
Most installations and service are regulated by local
regulations and building codes. Some or most of the
work outlines herein may require proper permitting
from the building department. Always assure to
follow all applicable rules and regulations.