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www.DaikinApplied.com 33
IM 893-10 • ROOFPAK SINGLEZONE UNITS
Table 13: Pressure-Vacuum Equivalents
Absolute pressure above zero
Vacuum below 1 atmosphere
Boiling point of H
2
O
at each pressure (°F)
Microns
PSIA
Mercury, in . (mm)
0
0
29.92 (760.0)
—
50
0.001
29.92 (759.95)
-50
100
0.002
29.92 (759.9)
-40
150
0.003
29.92 (759.85)
-33
200
0.004
29.91 (759.8)
-28
300
0.006
29.91 (759.7)
-21
500
0.009
29.90 (759.5)
-12
1,000
0.019
29.88 (759.0)
1
2000
0.039
29.84 (758.0)
15
4,000
0.078
29.76 (756.0)
29
6000
0.117
29.69 (754.0)
39
8,000
0.156
29.60 (752.0)
46
10,000
0.193
29.53 (750.0)
52
15,000
0.290
29.33 (745.0)
63
20,000
0.387
29.13 (740.0)
72
30,000
0.580
28.74 (730.0)
84
50,000
0.967
27.95 (710.0)
101
100,000
1.930
25.98 (660.0)
125
200,000
3.870
22.05 (560.0)
152
500,000
9.670
10.24 (260.0)
192
760,000
14.697
0
212
Charging the System
CAUTION
Adding refrigerant to the suction must always be done by
trained service personnel that are experienced with the risks
associated with liquid-related damage to the compressor.
CAUTION
Units purchased for R-410A operation must be charged only
with R-410A. Field mixing or changing of refrigerants can
compromise performance and damage equipment.
RCS units are leak tested at the factory and shipped with
a nitrogen holding charge. If the holding charge has been
lost due to shipping damage, then contact the factory for
authorization and advice for repairing the leak and evacuating
the system.
1. After all refrigerant piping is complete and the system
is evacuated, it can be charged as described in the
paragraphs following. Connect the refrigerant drum to
the gauge port on the liquid charging valve and purge
the charging line between the refrigerant cylinder and the
valve. Then open the liquid charging valve.
2. If the system is under a vacuum, stand the refrigerant
drum with the connection up, open the drum, and break
the vacuum with refrigerant gas.
3. With a system gas pressure higher than the equivalent of
a freezing temperature, invert the charging cylinder and
elevate the drum above the condenser. With the drum
in this position and the valves open, liquid refrigerant
flows into the condenser. Approximately 75% of the total
requirement estimated for the unit can be charged in this
manner.
4. After 75% of the required charge enters the condenser,
close the liquid charging valve and reconnect the
refrigerant drum and charging line to the suction side of
the system. Again, purge the connecting line and stand
the drum with the connection side up.
5. After charging is complete, torque the charging valve
stem to 15 ft-lb.
NOTE:
Use a backing wrench on the charging valve when
torquing to eliminate stress on the piping.
Mark the total operating charge per circuit on the unit
nameplate for future reference.
Take special care to add refrigerant slowly enough to the
suction to prevent damage when first adding charge to the
suction. Adjust the charging tank hand valve extremely slow
such that only liquid leaves the tank but vapor enters the
compressor.
Table 14: Acceptable Refrigerant Oils
R-410A (polyester [POE] oils)
Copeland ULtra 22 CC
Copeland ULtra 32-3MAF
ICI EMKARATE RL
™
32CL
Mobil EAL
™
Arctic 22 CC
Note:
Do not use mineral oils with R-410A.
