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Servicing Units 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 in figure
11.
2. Evacuate the system using procedure outlined in
figure 12.
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 figure 12.
5. Weigh in refrigerant using procedure outlined under
figure 19.
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 the liquid line and
suction line service valves to release the refrigerant
charge (contained in outdoor unit) into the system.
4. Replace the stem caps and tighten as specified in
Operating Service Valves
on page 9.
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 refrigerate using the
procedures that follow.
System Refrigerant
This section outlines procedures for:
1. Connecting gauge set for testing and charging;
2. Checking and adjusting indoor airflow;
3. Adding or removing refrigerant.
TO LIQUID
LINE SERVICE
VALVE
TEMPERATURE
SENSOR
DIGITAL SCALE
REFRIGERANT TANK
TEMPERATURE SENSOR
(LIQUID LINE)
MANIFOLD GAUGE SET
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.
OUTDOOR UNIT
CHARGE IN
LIQUID PHASE
CONNECTIONS FOR TESTING AND CHARGING
GAUGE SET
A
C
D
LOW
HIGH
B
SUCTION LINE
SERVICE PORT
CONNECTION
Figure 16. Gauge Set Setup and Connections
