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der with pressure regulator set to 150 psig (1034 kPa)
and purge the hose. Open the manifold gauge valves
to break the vacuum in the line set and indoor unit.
Close the manifold gauge valves.
WARNING
Danger of Equipment Damage.
Avoid deep vacuum operation. Do not use com-
pressors to evacuate a system.
Extremely low vacuums can cause internal arcing
and compressor failure.
Damage caused by deep vacuum operation will
void warranty.
7 − Shut off the nitrogen cylinder and remove the manifold
gauge hose from the cylinder. Open the manifold
gauge valves to release the nitrogen from the line set
and indoor unit.
8 − Reconnect the manifold gauge to the vacuum pump,
turn the pump on, and continue to evacuate the line set
and indoor unit until the absolute pressure does not
rise above 500 microns (29.9 inches of mercury) within
a 20−minute period after shutting off the vacuum pump
and closing the manifold gauge valves.
9 − When the absolute pressure requirement above has
been met, disconnect the manifold hose from the vacu-
um pump and connect it to an upright cylinder of R410A
refrigerant. Open the manifold gauge valves to break
the vacuum from 1 to 2 psig positive pressure in the line
set and indoor unit. Close manifold gauge valves and
shut off the R410A cylinder and remove the manifold
gauge set.
Start−Up
1 − Rotate fan to check for frozen bearings or binding.
2 − Inspect all factory− and field−installed wiring for loose
connections.
3 − After evacuation is complete, open the liquid line and
vapor line service valves to release the refrigerant
charge (contained in outdoor unit) into the system.
4 − Replace the stem caps and secure finger tight, then
tighten an additional one-sixth (1/6) of a turn.
5 − Check voltage supply at the disconnect switch. The
voltage must be within the range listed on the unit’s
nameplate. If not, do not start the equipment until you
have consulted the power company and the voltage
condition has been corrected.
6 − Set the thermostat for a high stage cooling demand (Y1
and Y2 demand). Turn on power to the indoor blower
and close the outdoor unit disconnect switch to start
the unit.
7 − Recheck voltage while the unit is running. Power must
be within range shown on the nameplate.
Charging
This system is charged with R410A refrigerant which oper-
ates at much higher pressures than HCFC−22. This unit is
NOT approved for use with coils which include metering
orifices or capillary tubes.
Processing Procedure
Units are factory charged with the amount of R410A refrig-
erant indicated on the unit rating plate. This charge is
based on a matching indoor coil and outdoor coil with 15
feet (4.6 m) line set. For varying lengths of line set, refer to
table 3 for refrigerant charge adjustment.
Table 3
Liquid Line Set
Diameter
Oz. per 5 ft. (grams per 1.5m) adjust
from 15 ft. (4.6 m) line set*
3/8 in.
(10 mm)
3 ounces per 5 feet
(85 g per 1.5 m)
*If line length is greater than 15 ft. (4.6 m), add this amount.
If line length is less than 15 ft. (4.6 m), subtract this amount.
IMPORTANT
Mineral oils are not compatible with R410A. If oil
must be added, it must be a polyol ester oil.
The compressor is charged with sufficient polyol ester
oil for line set lengths up to 50 feet (15.2 m).
If the system is void of refrigerant, clean the system us-
ing the procedure described below.
1 − Use nitrogen to pressurize the system and check for
leaks. Repair leaks, if possible.
2 − Evacuate the system to remove as much of the mois-
ture as possible (triple evacuation).
3 − Evacuate the system again. Then, weigh the appropri-
ate amount of R410A refrigerant (listed on unit name-
plate) into the system.
4 − Start the unit and monitor the system to determine the
amount of moisture remaining in the oil. Use test kit
10N46 to verify that the moisture content is within the
kit’s dry color range.
5 − If the moisture content is not within the dry color range,
add a new filter drier between the liquid valve and the
TXV. You may have to add a new filter drier several
times to achieve the required level of dryness.
If system dryness is not verified, the compressor
will fail in the future.
The outdoor unit should be charged during warm weather.
However, applications arise in which charging must occur
in the colder months. The method of charging is deter-
mined by the outdoor ambient temperature.
Measure the liquid line temperature and the outdoor ambi-
ent temperature as outlined below:
1 − Connect the manifold gauge set to the service valves:
low pressure gauge to vapor valve service port
high pressure gauge to liquid valve service port