Page 13
XC15 SERIES
ry). During the early stages of evacuation, it is desir-
able to close the manifold gauge valve at least once to
determine if there is a rapid rise in
absolute pressure
.
A rapid rise in pressure indicates a relatively large
leak. If this occurs, repeat the leak testing procedure.
NOTE − The term
absolute pressure
means the total
actual pressure within a given volume or system,
above the absolute zero of pressure. Absolute pres-
sure in a vacuum is equal to atmospheric pressure mi-
nus vacuum pressure.
6. When the absolute pressure reaches 23,000 microns
(29.01 inches of mercury), close the manifold gauge
valves, turn off the vacuum pump and disconnect the
manifold gauge center port hose from vacuum pump.
Attach the manifold center port hose to a dry nitrogen
cylinder 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 vacu-
um operation. Do not use compressors to evacu-
ate a system. Extremely low vacuums can cause
internal arcing and compressor failure. Damage
caused by deep vacuum operation will void war-
ranty.
7. Shut off the dry nitrogen cylinder and remove the man-
ifold gauge hose from the cylinder. Open the manifold
gauge valves to release the dry 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 vac-
uum pump and connect it to an upright cylinder of
R−410A 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 R−410A cylinder and remove
the manifold gauge set.
Start−Up
IMPORTANT
If unit is equipped with a crankcase heater, it should
be energized 24 hours before unit start−up to pre-
vent compressor damage as a result of slugging.
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 cooling demand. Turn on pow-
er to the indoor blower and close the outdoor unit dis-
connect switch to start the unit.
7. Recheck voltage while the unit is running. Power must
be within range shown on the nameplate.
Refrigerant Charging
This system is charged with R−410A refrigerant which op-
erates at much higher pressures than R−22. The provided
liquid line filter drier is approved for use with R−410A. Do
not replace it with components designed for use with R−22.
This unit is NOT approved for use with coils which use
cap-
illary tubes as a refrigerant metering device.
Factory Charge
Units are factory charged with the amount of R−410A re-
frigerant indicated on the unit rating plate. This charge is
based on a matching indoor coil and outdoor coil with 15 ft.
(4.6 m) line set. For varying lengths of line set, refer to table
3 for refrigerant charge adjustment.
Table 3
Refrigerant Charge per Line Set Lengths
Liquid Line
Set Diameter
Ounces per 5 feet (grams per 1.52 meter)
adjust from 15 ft. (4.57m) line set*
3/8 in. (9.5mm)
3 ounces per 5 feet (85 grams per 1.52 meter)
*Add the amount shown if line length is greater than 15’ (4.57m), sub-
tract the amount shown if less than 15’.
IMPORTANT
Mineral oils are not compatible with R−410A. If oil
must be added, it must be a polyol ester oil.
The compressor is charged with sufficient polyol
ester oil for approved line set lengths.
Units Delivered Void of Charge
If the system is void of refrigerant,
clean the system us-
ing the procedure described below.
1. Use dry 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.
3. Use dry nitrogen to break the vacuum and install a new
filter drier in the liquid line.
4. Evacuate the system again. Then, weigh the appropri-
ate amount of R−410A refrigerant (listed on unit name-
plate) into the system.
