Additional Refrigerant Charge - Trane MCD/MWD-512 Installation & Operation Manual

Creating a vacuum
For this operation, use a pump
capable of creating a vacuum of
1 mm Hg (1.3mbar) or less. To create
the vacuum you must connect the
pump to the Schrader pressure
connection on service valve
A located on the outdoor unit (gas
line). To use the vacuum pump,
follow the pump manufacturer's
instructions. Create a vacuum up to
2 mm Hg (2.6mbar) or less. Once the
value of 2mm Hg or less has been
reached, an increase in pressure will
be observed after a certain time. The
maximum permissible increase is
1 mm Hg after 15 minutes. If the
increase is greater and remains at a
constant value, this means there is
too much humidity in the system.
In this case, break the vacuum using
dry nitrogen and start the vacuum
creation procedure again.
A continuous increase in pressure
means there is a leak in the system.
WARNING!
Valves A and B must not be opened
before the installation of the
refrigerant circuit has been
completely finished, or the
refrigerant charge will be lost.
Figure 9 - Refrigerant circuit
1 = Outdoor unit
2 = Vacuum pump
3 = Indoor unit
4 = Gas line
5 = Liquid line
6 = TTK/TWK cooling mode
20
Operation
Additional refrigerant
charge
Once the system has been vacuum
pumped and is in operation and if
the distance between the units is
greater than 6m, it may be
necessary to add an additional
charge. Table 13 indicates the
amounts of refrigerant to add per
additional meter of line. Once the
appropriate amount of refrigerant
has been added, fully open liquid
line valve and check the operating
pressure.
Figure 10 - Adding refrigerant charge
A
1 = Outdoor unit
2 = Gas line
3 = Indoor units
4 = Liquid line
5 = For sizes 512 to 524
6 = For sizes 530 to 060
R22 Refrigerant
While the unit is operating, charge
the unit with gas through the service
Schraeder valve located at the
compressor suction. R22 refrigerant
can also be added in liquid phase in
the liquid line: see method used for
R407C. Never add liquid in the
suction line of the compressor.
R407C Refrigerant
add only R407C
WARNING!
refrigerant in liquid state. Never add
liquid in the suction line of the
compressor period. Use service
Schraeder valve located on the liquid
line to charge the unit. While the unit
is operating, close partially the
service valve in order to create a
lower pressure downstream the
service valve. Add the refrigerant
necessary. Control the added weight
with a scale.
Table 13 - Additional refrigerant charge
Liquid line Gas line
R22/R407C charge (g)
1/4'' 1/2''
5/16" 5/8"
3/8'' 5/8''
3/8'' 3/4''
3/8'' 7/8''
3/8'' 1 1/8''
SS-SVX07B-E4
Additional
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