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 18.
2.Evacuate the system using procedure outlined on page 19.
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 19.
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.
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.
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.
System Refrigerant
This section outlines procedures for:
1.Connecting gauge set for testing and charging (see figure 19.
2.Checking and adjusting indoor airflow as described in figure 20.
3.Add or remove refrigerant using the weigh in method provided in figure 21, and verifying charge using subcooling method described in figure 22.
GAUGE SET
CONNECTIONS FOR TESTING AND CHARGING
MANIFOLD GAUGE SET
LOW HIGH
B TRUE SUCTION PORT
CONNECTION
| REFRIGERANT TANK | |
| CHARGE IN | A |
| LIQUID PHASE | |
|
| |
| DIGITAL SCALE | |
INSIDE OUTDOOR UNIT |
| C |
D |
| TO LIQUID |
| LINE SERVICE | |
TEMPERATURE |
| VALVE |
SENSOR |
|
|
OUTDOOR UNIT
TEMPERATURE SENSOR
(LIQUID LINE)
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 true suction 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.
Figure 19. Gauge Set Connections
Page 27
XP17 SERIES
