Trane PTEC-070 Operation & Maintenance Manual page 27

PTEC-M-1A
Refrigeration
System
Charging
Charge the system with the exact
amount of refrigerant.
Refer to the unit nameplate for the
correct refrigerant charge. An
inaccurately charged system will
cause future problems.
1. When using an ambient
compensated calibrated charging
cylinder, allow liquid refrigerant
only to enter the high side.
2. After the system will take all it will
take, close the valve on the high
side of the manifold.
3. Start the system and charge the
balance of the refrigerant though
the low side. Do not charge in a
liquid form.
4. Close the low side valve on the
manifold and pinch-off both
process tubes. Remove the
manifold set, crimp shut the open
ends of the process tubes and
braze.
5. Recheck for refrigerant leaks.
Refrigerant
Do not use a refrigerant other than
that shown on the unit nameplate.
All precautionary measures
recommended by the refrigerant
manufacturers and suppliers should
be observed.
Line Piercing Valves
Line piercing valves may be used for
diagnosis but are not suitable for
evacuating or charging due to the
minute holes pierced in the tubing.
Line piercing valves must not be left
on the refrigerant system. The
connection between the valve and
the refrigerant tubing is not
hermetically sealed and will
eventually leak.
Open Lines
During any processing of the
refrigeration system the lines should
never be left open to atmosphere
since water vapor will enter and add
to the problem of proper evacuation.
Operating Test
The final step in a successful repair is
an accurate operating test. Follow
the Cooling and Heating
Performance tests provided to make
sure the product is again performing
to design standards.
Important Note: Never test operation
without the unit in the wall sleeve. A
serious change in design specifications
for air movement through the
evaporator and condenser
compartments, causing the fan motor to
over heat and the refrigeration system
to become unbalanced will occur when
the unit is not installed in the wall
sleeve.
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