16.0 CHECKING REFRIGERANT CHARGE
Charge for all systems should be checked against the Charging Chart inside the
access panel cover. Before using the chart, the indoor conditions must be within
2°F of desired comfort conditions and system must be run until operating conditions
stabilize (15 min. to 30 min.)
IMPORTANT:
Use industry-approved charging methods to ensure proper system
charge.
16.1 Charging units with R-410A Refrigerant
Charge for all systems should be checked against the Charging Chart inside the
access panel cover.
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.
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.
!
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.
!
CAUTION
THE TOP OF THE SCROLL COMPRESSOR SHELL IS HOT. TOUCHING THE
COMPRESSOR TOP MAY RESULT IN SERIOUS PERSONAL INJURY.
39
Summary of Contents for PRL-series
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