AAON CA-25 - Manual (Page 5)

5
WIRING DIAGRAMS
A complete set of unit wiring diagrams is provided and
located inside the control compartment door.
HEATING SYSTEMS
(optional as part of indoor air handler)
When heat is called for, the cooling section is inoper-
able except for the indoor blower motor. Actual heat-
ing is accomplished by an indoor air handling unit with
heating capabilities.
R22 LIQUID LINE CAPACITY
Pressure Loss = 3 PSI (1
°
F) at 100
°
F liquid
LIQUID LINE
The liquid line pipe size should be selected to have a
maximum pressure drop of 6 PSI which corresponds to
approximately 2
°
F with R22.
The CA condensing units have a built in filter drier. The
units do not include a liquid line solenoid valve and this
must be field furnished and installed if required by job
conditions.
(OPTIONAL) HOT GAS LINE
The hot gas bypass option is a system that maintains
evaporator pressure at or above a minimum value.
This will prevent the coil from freezing and also keep
the velocity of the refrigerant gas sufficiently high for
proper oil return to the compressor when the cooling
is at light load conditions.
Pressure drop in the hot gas line is normally designed
not to exceed the equivalent of a 2
°
F change in
saturation temperature. The recommended sizing
table below is based on a 1
°
F change in saturation
temperature.
Hot gas bypass lines must be insulated to minimize
heat loss and condensation of gas inside the piping
and to prevent injury from high temperature surfaces.
NOTE: Pressure loss, PSI/100 feet of equivalent line length
due to line friction. (Corresponding change in R22 satura-
tion temperature.)
R22 HOT GAS BYPASS LINE CAPACITY
Pressure Loss = 3 PSI (1
°
F) at 40
°
F saturated suction
NOTE: Pressure loss, PSI/100 feet of equivalent line length
due to line friction. (Corresponding change in R22 satura-
tion temperature.)
MINIMUM TONS CAPACITY
To Carry Oil Up a Suction Riser at 40
°
F saturated suction
FITTING LOSSES
In Equivalent Feet of Straight Copper Tubing
NOTE: The equivalent feet for a piping system must include
the equivalent length of straight tubing for all the fittings, as
well as, any valves that are added to the system.
WEIGHT OF REFRIGERANT 22
In Type L Copper Tubing (Pounds / 100 Feet)
Line Size - in.
3/8" 4.3 .065
1/2" 7.9 .120
5/8" 12.7 .195
7/8" 26.4 .405
1 1/8" 45.0 .690
1 3/8" 68.6 1.05
1 5/8" - - - 1.49
2 1/8" - - - 2.58
LIQUID AT 100
°
F SUCTION AT 40
°
F
Line
Size - in.
1/2" 1.4 0.9 2.3 0.7 1.1 2.3
5/8" 1.6 1.0 2.5 0.8 1.3 2.5
7/8" 2.0 1.4 3.2 0.9 1.6 3.2
1 1/8" 2.6 1.7 4.1 1.3 2.1 4.1
1 3/8" 3.3 2.3 5.6 1.7 3.0 5.6
1 5/8" 4.0 2.6 6.3 2.1 3.4 6.3
2 1/8" 5.0 3.3 8.2 2.6 4.5 8.2
90
°
Std.
90
°
LongRad
90
°
Street
45
°
Std.
45
°
Street
180
°
Std.
LINE SIZE - inches MAX. TONS / COMPRESSOR
1/2" 3.6
5/8" 6.7
7/8" 18.2
LINE SIZE - inches TONS / COMPRESSOR
1/2" 0.85
5/8" 1.6
7/8" 4.2
1 1/8" 8.5
1 3/8" 14.8
LINE SIZE - inches Min. TONS / COMPRESSOR
3/4" 0.8
7/8" 1.1
1 1/8" 1.8
1 3/8" 2.9
1 5/8" 4.0
2 1/8" 7.2