Start−Up; Refrigerant Charge; Checking Indoor Airflow - Lennox 14HPX?018 Installation Instructions Manual

WARNING
Danger of Equipment Damage. Avoid deep
vacuum operation. Do not use compressors 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 vac-
uum pump and connect it to an upright cylinder of
HFC−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 HFC−410A cylinder and
remove the manifold gauge set.
Start−Up
IMPORTANT
Crankcase heater
energized 24 hours before unit start−up to prevent
compressor damage as a result of slugging.
1. Check that fan rotates freely.
2. Inspect all factory and field-installed wiring for loose
connections.
NOTE − After the system has been evacuated and before
completing all the remaining start−up steps, this is the ideal
time to adjust the amount of refrigerant made necessary by
line set length difference and by the specific indoor unit
505243 05/08
(if applicable) should
matchup. Skip to the paragraph Setup for Checking and
Adding Charge" on Page 13 to setup for charging and for
determine if charge is needed; adjust the charge accord-
ingly.
3. Open the liquid line and vapor line service valves
(counterclockwise) to release refrigerant charge (con-
tained in outdoor unit) into the system.
4. Replace stem caps and tighten finger tight; then tighten
per table 1 (on page 3).
5. Check voltage supply at the disconnect switch. The
voltage must be within the range listed on the unit
nameplate. If not, do not start the equipment until the
power company has been consulted and the voltage
condition has been corrected.
6. Set the thermostat for a cooling demand, turn on pow-
er to indoor blower unit and close the outdoor unit dis-
connect to start the unit.
7. Recheck voltage while the unit is running. Power must
be within range shown on the nameplate.

Refrigerant Charge

This system is charged with HFC−410A refrigerant which
operates at much higher pressures than HCFC−22. The
recommended check expansion valve is approved for use
with HFC−410A. Do not replace it with a valve that is de-
signed to be used with HCFC−22. This unit is NOT ap-
proved for use with coils that include metering orifices or
capillary tubes.
The unit is factory−charged with the amount of HFC−410A
refrigerant indicated on the unit rating plate. This charge is
based on a matching indoor coil and outdoor coil with a 15
foot (4.6 m) line set. A blank space is provided on the unit
be
rating plate to list the actual field charge.
Mineral oils are not compatible with HFC−410A. If
oil must be added, it must be a polyol ester oil.

Checking Indoor Airflow

NOTE − Be sure that filters and indoor and outdoor coils are
clean before testing.
Page 12
IMPORTANT