8
Service Facts
CHARGING IN COOLING ABOVE 55°F OD
AMBIENT
The preferred method is to weigh in the factory charge
per the unit nameplate. If weighing in the charge is not
practical, the following method can be used. The fol-
lowing charging method is prescribed for systems with
indoor TXVs.
1. For best results – the indoor temperature should be kept
between 70°F to 80°F. Add system heat if needed.
2. Whenever charge is removed or added, the system must
be operated for a minimum 20 minutes to stabilize before
accurate measurements can be made.
3. Measure Liquid Line Temperature and Refrigerant Pres-
sure at service valves in the compressor compartment.
4. Locate your liquid line temperature in the left column of
the table, and the intersecting liquid line pressure under
the subcool value column. Add refrigerant to raise the
pressure to match the table, or remove refrigerant to
lower the pressure. Again, wait 20 minutes for the sys-
tem conditions to stabilize before adjusting charge again.
5. When system is correctly charged, you can refer to
System Pressure Curves (on page 2) to verify typical
performance.
R-410A Subcooling Charging Table
10 (ºF) Subcooling
Liquid Liquid
Temperature Pressure
(ºF) PSIG
55 185
60 200
65 217
70 235
75 254
80 274
85 295
90 317
95 340
100 364
105 390
110 417
115 445
120 475
125 506
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