Allied Air Enterprises 4AC18LT Start-Up, Refrigerant Charging, Refrigerant Charge Adjustment

START-UP

CAUTION

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 frozen bearings or binding.

2.Inspect all factory and field-installed wiring for loose connections.

3.After evacuation is complete, open liquid line and suction line service valves to release refrigerant charge (contained in outdoor unit) into system.

4.Replace the stem caps and secure finger tight, then tighten an additional 1/6 of a turn.

5.Check voltage supply at the disconnect switch. The voltage must be within the range listed on the unit nameplate. If not, do not start equipment until the power company has been consulted and the voltage condition corrected.

6.Set thermostat for cooling demand, turn on power to indoor blower, and close the outdoor unit disconnect switch to start the unit.

7.Recheck unit voltage with unit running. Power must be within range shown on unit nameplate.

Refrigerant Charging

This system is charged with R410A refrigerant which operates at much higher pressures than R-22. The liquid line drier provided with the unit is approved for use with R410A. Do not replace it with one designed for use with R-

22.This unit is NOT approved for use with coils which use capillary tubes as a refrigerant metering device.

R410A refrigerant cylinders are rose colored. Refrigerant should be added through the suction valve in the liquid state.

Certain R410A cylinders are identified as being equipped with a dip tube. These allow liquid refrigerant to be drawn from the bottom of the cylinder without inverting the cylinder. Do not turn this type of cylinder upside down to draw refrigerant.

Units are factory charged with the amount of R410A refrigerant indicated on the unit rating plate. This charge is based on a matching indoor coil and outdoor coil with 15’ line set. For varying lengths of line set, refer to Table 5 for refrigerant charge adjustment. A blank space is provided on the unit rating plate to list the actual field charge.

Refrigerant Charge Adjustment

Liquid Line Set	Oz. per 5 ft. adjust
Diameter	from 15 ft. line set*
3/8 in.	3 oz. Per 5 ft.

*If line length is greater than 15 ft., add this amount. If line length is less than 15 ft., remove this amount.

Table 5

IMPORTANT

Mineral oils are not compatible with R410A. If oil must be added, it must be a polyolester oil.

If the system is void of refrigerant, clean the system using the procedure described below.

1.Use dry nitrogen to pressurized the system and check for leaks. Repair leaks, if possible.

2.Evacuate the system to remove as much of the moisture as possible.

3.Use dry nitrogen to break the vacuum.

4.Evacuate the system again.

5.Weigh the appropriate amount of R410A refrigerant (listed on unit nameplate) into the system.

6.Monitor the system to determine the amount of moisture remaining in the oil. Use a test kit to verify that the moisture content is withing the kit’s dry color range. 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.

The outdoor unit should be charged during warm weather. However, applications arise in which charging must occur in the colder months. The method of charging is determined by the unit’s refrigerant metering device and the outdoor ambient temperature.

Measure the liquid line temperature and the outdoor ambient temperature as outlined below:

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