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Installation
R407C Refrigerant
CeilAir TR-OHS systems use either R407C refrigerant.
Refrigerant charging pressures vary depending on the
type of refrigerant used in the unit. Before charging, check
the unit nameplate to confirm the type of refrigerant to
use. Tables are provided in Section
Characteristics," p. 30
showing the temperature/pressure
characteristics for R407C.
Important:
R407C can contribute to the green- house
effect if released. Avoid releasing the
refrigerant into the atmosphere.
WARNING
Refrigerant Vapor Hazard!
Refrigerant vapors may collect and concentrate in
confined spaces or low lying areas which will result in
the displacement of air. This poses a potential health
risk due to suffocation. Failure to follow proper
handling guidelines could result in death or serious
injury.
Refer to the appropriate SDS sheets and OSHA/GHS
guidelines for information referring to allowable
personal exposure levels and handling guidelines.
R407C are multi-component blends whose component
parts have different volatilities that result in a change in
composition and saturation temperature as evaporation
and condensation occur. Typically, the com- position of
R407C vapor is different than that of R407C liquid within a
contained system. The composition of liquid R407C
refrigerant remains relatively constant, however, the
refrigerant vapor tends to separate into its component
parts even when circulating.
Estimating Refrigerant Charge
When charging a system with R407C refrigerant it will be
necessary to weigh in the refrigerant and confirm by
checking the superheat and sub-cooling temperatures
(see"Pressure/Temperature Settings," p.
minimum amount of refrigerant needed by adding the
amount of refrigerant required for the condenser (see the
condenser manual provided separately) plus the
refrigerant piping
(Table 6, p.
the A/C unit
(Table 7, p.
28). The values in
the estimated weights for the compressor circuit. In the
case of dual compressor systems, the values are
estimated weights for each compressor circuit. The values
shown in
Table 7, p. 28
are conservative for the purpose of
preventing the system from being overcharged.
Table 6.
Weight (lb) of refrigerant per 100 of type L
tubing
Line Size
(in.)
Liquid Line
O.D.
I.D.
R407C
3/8
0.315
3.42
1/2
0.43
6.37
28
"Refrigerant
30). Calculate the
28) plus the refrigerant for
Table 8, p. 31
are
Discharge Line
R407C
0.7
1.3
Table 6.
Weight (lb) of refrigerant per 100 of type L
tubing (continued)
Line Size
(in.)
Liquid Line
O.D.
I.D.
R407C
5/8
0.545
10.24
7/8
0.785
21.24
1-1/8
1.025
36.21
1-3/8
1.265
55.15
Table 7.
Weight (lb) of refrigerant by TR-OHS model
TR-OHS Model
Base Charge (Per
Number
Circuit)
Approximate R407C Charge
-012-AR
0.9
-018-AR
0.9
-024-AR
0.9
-032-AR
1.9
-040-AR
1.9
-048-AR
3.6
-048-DAR
1.0
-060-AR
3.6
-072-DAR
2.5
-084-DAR
2.5
-120-DAR
3.9
Preparing System For Charging
1. With all the system piping connections made, perform
a dry nitrogen leak detection test on the system. Using
dry nitrogen only, pressurize the system to 150 psig.
Ensure all service and solenoid valves are energized
open and that no part of the system is isolated from the
pressurized nitrogen (liquid, suction or discharge lines
and reheat coil).
2. Since there is no refrigerant in the system to detect at
this point, leaks may be detected by observing if
there's been a change in the standing pressure after 12
hours. A significant drop in pressure (>10 psig)
indicates a leak in the system that needs to be repaired.
After the system is determined to be free of leaks, you
may evacuate the system.
Discharge Line
R407C
2.1
4.35
7.41
11.29
Flooded HP Control
Charge Adder
8.0
8.0
8.0
9.8
9.8
15.3
9.8
15.3
9.8
9.8
15.3
AH-SVX008C-EN
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