8
NOTE: Superheat adjustments should not be made
until indoor ambient conditions have stabilized.
This could take up to 24 hours depending on
indoor temperature and humidity. Before checking
superheat run the unit in cooling for 10-15 minutes
or until refrigerant pressures stabilize. Use the
following guidelines and methods to check unit
operation and ensure that the refrigerant charge
is within limits.
The outdoor temperature must be 60°F or higher. Set the
room thermostat to COOL, fan switch to AUTO, and set the
temperature control well below room temperature.
Units matched with indoor coils equipped with a non-
adjustable TXV should be charged by Subcooling only.
Superheat on indoor coils with adjustable TXV valves are
factory set and no adjustment is normally required during
startup. Only in unique applications due to refrigerant
line length, differences in height between the indoor
and outdoor unit and refrigerant tubing sizes or poor
performance should Superheat setting require adjustment.
These adjustments should only be performed by
qualified service personnel. For detailed charge and TXV
adjustments refer to the appropriate Service Manual.
Fixed Orifice
CAUTION
To prevent personal injury, carefully connect and
disconnect manifold gauge hoses. Escaping liquid
refrigerant can cause burns. Do not vent refrigerant into
the atmosphere. Recover all refrigerant during system
repair and before final unit disposal.
1.
Purge gauge lines. Connect service gauge manifold
to base-valve service ports. Run system at least 10
minutes to allow pressure to stabilize.
2.
Temporarily install a thermometer 4-6” from
the compressor on the suction line. Ensure the
thermometer makes adequate contact and is insulated
for best possible readings. Use vapor temperature to
determine superheat.
3. Refer to the superheat table provided for proper
system superheat. Add charge to lower superheat or
recover charge to raise superheat.
4. Disconnect manifold set, installation is complete.
Superheat Formula = Suct. Line Temp. - Sat. Suct.
Temp.
