Charging By Liquid Pressure; Charging By Weight; Final Leak Testing - Rheem R-410A Installation Instructions Manual

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IMPORTANT: Do not operate the compressor without charge in system.
Addition of R-410A will raise pressures (vapor, liquid and discharge).
If adding R-410A raises both vapor pressure and temperature, the unit is over-
charged.
IMPORTANT: Use industry-approved charging methods to ensure proper system
charge.
CAUTION
R-410A PRESSURES ARE APPROXIMATELY 60% HIGHER THAN R-22
PRESSURES. USE APPROPRIATE CARE WHEN USING THIS REFRIGER-
ANT. FAILURE TO EXERCISE CARE MAY RESULT IN EQUIPMENT DAM-
AGE, OR PERSONAL INJURY.

16.2 Charging By Liquid Pressure

Liquid pressure method is used for charging systems in the cooling and heating
mode. The service port on the liquid service valve (small valve) and suction (large
valve) is used for this purpose.
Verify that the outdoor unit is running and the indoor air mover is delivering the
maximum airflow for this system size. Read and record the outdoor ambient tem-
perature. Read and record the liquid and suction pressures at the ports on the liquid
and suction valves. If refrigerant lines are sized using the nameplate charge, the
correct liquid pressure is found at the intersection of the suction pressure and the
outdoor ambient.
1. Remove refrigerant charge if the liquid pressure is above the chart value.
2. Add refrigerant charge if the liquid pressure is below the chart value.

16.3 Charging By Weight

For a new installation, evacuation of interconnecting tubing and indoor coil is ade-
quate; otherwise, evacuate the entire system. Use the factory charge shown in
Table 1 of these instructions or unit data plate. Note that charge value includes
charge required for 15 ft. of standard size interconnecting liquid line. Calculate actu-
al charge required with installed liquid line size and length using:
1/4" O.D. = .3 oz./ft.
5/16" O.D. = .4 oz./ft.
3/8" O.D. = .6 oz./ft.
1/2" O.D. = 1.2 oz./ft.
With an accurate scale (+/– 1 oz.) or volumetric charging device, adjust charge dif-
ference between that shown on the unit data plate and that calculated for the new
system installation. If the entire system has been evacuated, add the total calculat-
ed charge.
NOTE: The optimum refrigerant charge for the (-)PRL-036 & (-)PRL-048 is affected
more by the application than other (-)PRL models due to the relationship between
the indoor and outdoor volumes. Therefore, if charging by weight on these two
models, the net refrigerant charge must be reduced if the application utilizes an air-
handler in the downflow or horizontal right configuration or in dual fuel applications
(coil installed on a gas furnace). The recommended net charge reduction for down-
flow/horizontal right air-handler and dual fuel applications is shown on the applica-
ble charging chart attached to the (-)PRL-036 & (-)PRL-048. It is highly recommend-
ed that the refrigerant charge also be checked and adjusted based on the appropri-
ate charging chart once the unit is put into operation.

16.4 Final Leak Testing

After the unit has been properly evacuated and charged, a halogen leak detector
should be used to detect leaks in the system. All piping within the condensing unit,
evaporator, and interconnecting tubing should be checked for leaks. If a leak is
detected, the refrigerant should be recovered before repairing the leak. The Clean
Air Act prohibits releasing refrigerant into the atmosphere.