Procedure When Servicing The Indoor Unit Refrigeration Circuit - Pioneer WYC009AMFI20 Service Manual

1). 1st step; Connect the low pressure gauge
from the gauge manifold set to the 3 way
service valve (this is the blue hose on most sets)
2nd step; 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.
3rd step; 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.
3) Next step is to 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.
4) Start the unit in the cooling mode and lower
the set point so the unit wont shut off during the
charging procedure.
5) Refrigerant can now be added to the system,
open the low pressure valve on the gauge
manifold set to start charging the unit with liquid
refrigerant, keep track of the refrigerant being
added to the system (do not overcharge the
system)
6). Once 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.
7). Mount the valve stem caps and the service
port
Use torque wrench to tighten the service port
cap to a torque of 18N.m(13.27 ft,lbs).
Always leak check
refrigerant system.
after servicing the
6.6 Procedure when servicing the indoor
unit refrigeration circuit.
1. Pumping down the system (isolating the
refrigerant charge in the condensing unit)
Procedure
1). With the unit in the cooling mode and a low
set point remove all caps from the 3 way and 2
way valves, next attach the low pressure gauge
to the 3 way service valve port and purge the air
from that hose by loosening the hose at the
manifold for a second, be sure the low pressure
gauge valve is closed. 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 prepare to
close both valves on the unit starting with the 2
way valve (this is called front seating the valve)
also prepare to shut the power off to the outdoor
unit.
2). Connect the charge hose with the push pin
of handle lo to the 3-way valves gas service
port.
3). Air purging of the charge hose.
Open the handle Lo valve of the manifold valve
slightly to purge air from the charge hose for 5
seconds and then close it quickly.
4). Now close the 2 way valve and monitor the
low pressure gauge. the pressure will start to
drop.
5). Operate the unit in the cooling mode and
disconnect the power to the outdoor unit when
the low side gauge reads a slight vacuum,
running the compressor in a vacuum could
damage the motor windings. Note that units with
extended lines and additional refrigerant charge
may not be able to achieve a vacuum, this
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is