Stulz FLAIR series, Installation, Operation And Maintanance Manual

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(©Aug, 2007)
FLAiR Series Installation, Operation & Maintenance Manual
Air Technology Systems, Inc.
2-13
NOTE
Under cold climate conditions it is recommended
to do the following:
6. Block off the intake air to the condenser with
cardboard until a constant discharge pressure
(225-280 psig) can be obtained. This will lower the
possibility of overcharging and avoid the occa-
sional bubbles that may appear in the sight glass
during fan cycling. (For units with fan cycling only.)
7. If the unit has a hot gas reheat option, the previous
steps are still followed except the hot gas reheat
valve must be opened to allow refrigerant to flow
into the reheat coil to obtain the proper amount of
unit charge. This process may need to be re-
peated several times, which can be done by
enabling a call for dehumidification. After cycling
the system through the hot gas reheat cycle,
recheck the system charge in the
COOLING-ONLY mode.
8. Ensure the crankcase heater is operational by
checking the amperage.
CAUTION
Remove the blockage to the air intake of the
condenser.
9. Fill out applicable sections of Warranty Registra-
tion and Start-Up Checklist.
2.8.1.2.2 -30ºF Flooded Head Pressure Control
The following instructions are for charging systems with
flooded head pressure control using R22 refrigerant.
1. Bleed air from hoses and "break" the system
vacuum by supplying R22
liquid to the service valve
of the receiver until the receiver is full. Then supply
R22
vapor to the suction port until the pressure is
raised to about 50 psig (low pressure switch
makes).
2. Start the system and use the microprocessor
controller to lower the temperature set-point 3-5°F
below room temperature. This will ensure cooling
remains on during charging procedure.
CAUTION
An adequate heat load must be supplied to the
unit to ensure a proper charge.
3. After starting the system, immediately supply
R22
vapor to the suction port until the liquid line
sight glass has cleared of all bubbles.
4. Raise the discharge pressure to 300-325 psig and
hold it constant by blocking the air intake of the
condenser.
5. Once the discharge pressure has stabilized for 5 to
10 minutes, additional refrigerant R22 vapor must
be added to the suction port until the "float ball" in
the level indicator of the receiver begins to float.
CAUTION
Remove the blockage to the air intake of the
condenser.
6. Take a superheat temperature reading on the
suction line near the feeler bulb from the thermal
expansion valve. The ideal superheat temperature
is 12-15°F. The maximum allowable superheat
temperature is 20°F.
7. Ensure that the crankcase heater is operational by
checking the amperage.
8. Fill out applicable sections of Warranty Registra-
tion and Start-Up Checklist.
2.8.2 R407C Refrigerant Charging
Procedures
R407C is a blended refrigerant recognized for being
safer for the environment. R407C refrigerant contains
no chlorine, the component in HCFC’s that destroy
the earth’s ozone layer. However, the same care
should be taken to prevent leakage because R407C
can contribute to the greenhouse effect if released.
Refrigerants that are multi-component blends have
component parts with different volatilities that result in
a change in composition and saturation temperature
as evaporation and condensation occur. Typically, the
composition of R407C vapor is different than that of
R407C liquid within a contained system. The compo-
sition of liquid R407C refrigerant remains relatively