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 in this instruction.

2.Evacuate the system using procedure outlined in this instruction.

3.Use nitrogen to break the vacuum and install a new filter drier in the system.

4.Evacuate the system again using procedure outlined in this instruction.

5.Weigh in refrigerant using procedure outlined under Start−Up and Charging Procedures.

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.

3.After evacuation is complete, open the liquid line and suction line service valve stems (Operating Service Valves on page 4) 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.Connect manifold gauge set for testing and charging using figure 18 as a guideline.

7.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.

8.Recheck voltage while the unit is running. Power must be within range shown on the unit nameplate.

9.Check system for sufficient refrigerate using the procedures outlined in under System Refrigerant.

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.

GAUGE SET

 

MANIFOLD GAUGE SET

CONNECTIONS FOR TESTING AND CHARGING

LOW

HIGH

 

 

 

SUCTION LINE

 

 

 

B SERVICE PORT

 

 

 

CONNECTION

 

 

OUTDOOR UNIT

 

 

 

 

AClose manifold gauge set valves and connect

 

 

 

 

the center hose to a cylinder of HFC−410A.

 

REFRIGERANT TANK

 

Set for liquid phase charging.

 

 

 

 

 

 

BConnect the manifold gauge set’s low pressure

 

 

 

 

side to the suction line service port.

CHARGE IN

A

 

LIQUID PHASE

 

 

 

 

CConnect the manifold gauge set’s high

 

 

 

 

pressure side to the liquid line service port.

 

 

 

 

DPosition temperature sensor on liquid line near

 

DIGITAL SCALE

 

 

 

 

 

liquid line service port.

 

 

 

 

 

 

 

C

TEMPERATURE SENSOR

 

 

 

(LIQUID LINE)

 

 

 

TO LIQUID

 

 

 

 

 

 

 

LINE SERVICE

 

 

 

 

VALVE

 

DTEMPERATURE

SENSOR

Figure 18. Manifold Gauge Set Setup and Connections

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Lennox International Inc CONDENSING UNITS Servicing Units Delivered Void of Charge, Unit Start−Up, System Refrigerant