Unit Start−Up; System Refrigerant - Lennox XC21 Series Unit Information

Unit Start−Up
IMPORTANT
If unit is equipped with a crankcase heater, it should be
energized 24 hours before unit start−up to prevent
compressor damage as a result of slugging.
1. Rotate fan to check for binding.
2. Inspect all factory− and field−installed wiring for loose
connections.
3. After evacuation is complete, open both the liquid and
vapor line service valves to release the refrigerant
charge contained in outdoor unit into the system.
4. Replace the stem caps and tighten to the value listed
in table 1.
5. Check voltage supply at the disconnect switch. The
voltage must be within the range listed on the unit's
GAUGE SET
CONNECTIONS FOR TESTING AND CHARGING
A Close manifold gauge set valves and connect the center hose to a cylinder of HFC−410A. Set for liquid phase charging.
B Connect the manifold gauge set's low pressure side to the suction line service port.
C Connect the manifold gauge set's high pressure side to the liquid line service port.
D Position temperature sensor on liquid line near liquid line service port.
SUCTION LINE
B
SERVICE PORT
CONNECTION
REFRIGERANT TANK
CHARGE IN
LIQUID PHASE
DIGITAL SCALE
TEMPERATURE
D
SENSOR
Figure 13. Gauge Set Setup and Connections
Page 27
nameplate. If not, do not start the equipment until you
have consulted with the power company and the
voltage condition has been corrected.
6. Set the thermostat for a cooling demand. Turn on
power to the indoor indoor unit 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.
8. Check system for sufficient refrigerant by using the
procedures listed under System Charge.

System Refrigerant

This section outlines procedures for:
1. Connecting gauge set for testing and charging;
2. Checking and adjusting indoor airflow;
MANIFOLD GAUGE SET
HIGH
LOW
A
TEMPERATURE SENSOR
C
(LIQUID LINE)
TO LIQUID
LINE SERVICE
VALVE
OUTDOOR UNIT
XC21