SECTION VI: SYSTEM CHARGE
Refrigerant charging should only be carried out by a qualified air conditioning contractor.
R-410A refrigerant cylinders are rose colored, and have a dip tube which allows liquid to flow out of the cylinder in the Upright Posi- tion. Always charge the system slowly with the tank in the upright position.
DO NOT attempt to pump “Total System Charge” into outdoor unit for maintenance, service, etc. This may cause damage to the com- pressor and/or other components. the outdoor unit only has enough volume for the factory charge, not the “Total System Charge”.
1.The factory charge in the outdoor unit includes enough charge for the unit, a 15 ft. line set and the smallest rated indoor coil match-up. Some indoor coil matches may require additional charge. See tabu- lar data sheet provided in unit literature packet for charge require- ments.
2.Once line size/length and indoor coil adders have been figured, weigh in this amount of charge by adding it through the liquid service port while the indoor side of the system is still under a vacuum. The vacuum that is on the indoor side of the system will allow you to add most of the charge adder. If you are not able to add the full amount then add the remainder after starting up the system to verify proper subcooling. The subcooling charging method is explained further in this section.
3.Release the refrigerant charge from the outdoor unit into the system. Open both the liquid and vapor service valves at outdoor unit by removing the plunger cap and with an allen wrench back out coun- ter-clockwise until valve stem just touches the chamfered retaining wall. ”PRECAUTIONS DURING BRAZING SERVICE VALVE”.
4.Replace plunger cap finger tight, then tighten an additional 1/12 turn (1/2 hex flat). Cap must be replaced to prevent leaks.
5.Use the following subcooling charging method whenever additional refrigerant is required for the system charge. A superheat charging method is not suitable for TXV equipped systems.
Measurement Method
If a calibrated charging cylinder or accurate weighing device is avail- able, add refrigerant accordingly.
Compressor damage will occur if system is improperly charged. On new system installations, charge system per tabular data sheet for the matched coil and follow guidelines in this instruction.
Subcooling Charging Method
This condensing unit must only be used with the matching thermostatic expansion valve kit listed in the Tabular Data Sheet. This unit must be charged during cooling operation (Y1) operation only. Charging should be matched per the subcooling chart located on the rating plate.
1.Set the system running in the cooling (Y1) cooling mode by setting the thermostat at least 6°F below the room temperature.
2.Operate the system for a minimum of 15-20 minutes.
3.Refer to the Tech Guide for the recommended airflow and verify this indoor airflow (it should be about 400 SCFM per ton).
4.Measure the liquid refrigerant pressure P and temperature T at the service valve.
5.Calculate the saturated liquid temperature ST from Table 1 "R-410A Saturation Properties".
6.Subcooling temperature TC = Saturated Temperature (ST) - Liquid Temp (T).
Example: The pressure P and temperature T measured at the liquid service port is 360 Psig and 93°F. From Table 1, the saturated tem- perature for 360 Psig is 109°. The subcooling temperature TC = 109°-93°=16°F
Add charge if the calculated subcooling temperature TC in Step 6 is lower than the recommended level. Remove and recover the refrigerant if the subcooling TC is higher than the recommended level. See Table 1 for R-410A saturation temperatures.
After disconnecting manifold gauge set check flare caps on service ports to be sure they are leak tight. DO NOT OVERTIGHTEN (between 40 and 60 inch - lbs. maximum).
The “Total System Charge” must be permanently stamped on the unit data plate.
Total system charge is determined as follows:
1.Determine outdoor unit charge from tabular data sheet.
2.Determine indoor coil adjustment from tabular data sheet.
3.Calculate the line charge using the tabular data sheet if line length is greater than 15 feet.
4.Total system charge = item 1 + item 2 + item 3.
5.Permanently stamp the unit data plate with the total amount of refrig- erant in the system.
SECTION VII: INSTRUCTING THE OWNER
Assist owner with processing warranty cards and/or online registration. Review Owners Manual, provide a copy to the owner, and provide guid- ance on proper operation and maintenance. Instruct the owner or the operator how to start, stop, and adjust temperature setting.
The installer should also instruct the owner on proper operation and maintenance of all other system components.
MAINTENANCE
1.Dirt should not be allowed to accumulate on the outdoor coils or other parts in the air circuit. Clean as often as necessary to keep the unit clean. Use a brush, vacuum cleaner attachment, or other suitable means.
2.The outdoor fan motor is permanently lubricated and does not require periodic oiling.
