Unit installation

IOMM ACZ1-2 ACZ 010A through 039A 31
Table 13, R-22 Saturated Temperatures
Pressure (psi) Temperature (
o
F)
24.0 0
34.7 12.0
47.6 24.0
62.8 36.0
80.8 48.0
101.6 60.0
126.2 72.0
153.8 84.0
185.2 96.0
220.6 108.0
260.5 120.0
305.2 132.0
355.1 144.0
430.4 160.0
R407C Saturated Temperature
Evaporator dew point and condenser mid point are calculated using 32 bit math. The
equation is as follows:
If Pressure < 120 psi Then
Saturation = [Pressure x 145/105] – [(Pressure
2
)/2000] – 250
If Pressure >= 120 psi Then
Saturation = [Pressure x 46/94] – [Pressure
2
/25000] + 145
Pumpdown Pressure
The pressure to which a circuit will pumpdown is based on the Low Evaporator Pressure
Unload setpoint. The equation is as follows:
Pumpdown pressure = Low Evaporator Pressure Unload Setpoint – 15 psi (with the
calculated value limited to a minimum of 10 psi).
Unit Enable
The Unit Enable status determines whether the unit is enabled to run or not. This can be
altered by the Unit Switch input, Remote input, Keypad entry, and BAS request. The
Control Source Setpoint determines which sources can change the Unit Enable status with
options of SWITCHES, KEYPAD or NETWORK.
Changing the Unit Enable status can be accomplished according to the following table.
NOTE: An “x” indicates that the value is ignored.
Unit
Switch
Control Source
Setpoint
Remote
Input
Keypad
Entry
BAS
Request
Unit
Enable
OFF x x x x OFF
x SWITCHES OFF x x OFF
ON SWITCHES ON x x ON
ON KEYPAD x OFF x OFF
ON KEYPAD x ON x ON
ON NETWORK x x OFF OFF
ON NETWORK OFF x x OFF
ON NETWORK ON x ON ON