Servicing Unit Delivered Void Of Charge; Unit Start−Up; System Refrigerant - Lennox Collection XC21 System Installation Instructions Manual

Servicing Units Delivered Void of Charge
If the outdoor unit is void of refrigerant, clean the system
using the procedure described below.
1. Leak check system using procedure outlined on page
17.
2. Evacuate the system using procedure outlined on
page 18.
3. Use nitrogen to break the vacuum and install a new
filter drier in the system.
4. Evacuate the system again using procedure outlined
on page 18.
5. Weigh in refrigerant using procedure outlined in figure
21.
6. Monitor the system to determine the amount of
moisture remaining in the oil. It may be necessary to
replace the filter drier several times to achieve the
required dryness level. If system dryness is not
verified, the compressor will fail in the future.
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.
GAUGE SET
COnNECTIOnS FOR TESTING
AND CHARGING
AClose manifold gauge set valves and connect the center hose to a cylinder of HFC−410A. Set for liquid phase charging.
BConnect the manifold gauge set's low pressure side to the suction line service port.
CConnect the manifold gauge set's high pressure side to the liquid line service port.
DPosition temperature sensor on liquid line near liquid line service port.
SUCTION LINE
B
SERVICE PORT
CONNECTION
CHARGE IN
LIQUID PHASE
D
TEMPERATURE
SENSOR
Figure 18. Gauge Set Setup and 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
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 Refrigerant.

System Refrigerant

This section outlines procedures for:
1. Connecting gauge set for testing and charging (see
figure 18.
2. Checking and adjusting indoor airflow as described in
figure 19.
3. Adding or removing refrigerant. Use figure 20 to
determine the best method for charging the system.
When using weigh in method use procedure provided
in figure 21, and verifying charge using methods
described in figures 22 or 23.
LOW
REFRIGERANT TANK
A
DIGITAL SCALE
C
TO LIQUID
LINE SERVICE
VALVE
Page 25
HIGH
MANIFOLD GAUGE SET
OUTDOOR UNIT
SERVICE VALVE
TEMPERATURE SENSOR
(LIQUID LINE)
VAPOR LINE
LIQUID LINE
SERVICE VALVE
XC21 SERIES