Specifications

15
13.0 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: Do not operate the compressor without charge in system.
Addition of R-410A will raise pressures (vapor, liquid and discharge) and lower
vapor temperature.
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.
13.1 CHARGING USING CHARGING CHART
NOTE: THIS UNIT CONTAINS R-410A REFRIGERANT.
DO NOT CHARGE WITH R-22 REFRIGERANT.
The liquid pressure method is used for charging systems in the cooling mode. The
service port on the liquid (small valve) and suction (large valve) is used for this pur-
pose.
Verify that the outdoor unit is running in the cooling mode and the indoor air mover
is delivering the maximum airflow for this system size. Read and record the outdoor
ambient temperature. 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.
If the refrigerant lines utilize extended lengths, add 4 psi to the liquid pressure val-
ues shown in the chart.
1. Remove refrigerant charge if the refrigerant liquid pressure is above the cor-
rected chart value.
2. Add refrigerant charge if the liquid pressure is below the corrected chart value.
13.2 CHARGING BY WEIGHT
For a new installation, evacuation of interconnecting tubing and evaporator coil is
adequate; 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. = 0.2 oz./ft.
5/16” O.D. = 0.3 oz./ft.
3/8” O.D. = 0.5 oz./ft.
1/2” O.D. = 1.0 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: When the total refrigerant charge volume exceeds the values in Table 7, the
manufacturer recommends installing a crankcase heater and start kit.
!
CAUTION
THE TOP OF THE SCROLL COMPRESSOR SHELL IS HOT. TOUCHING THE
COMPRESSOR TOP MAY RESULT IN SERIOUS PERSONAL INJURY.
!
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.