Unit installation

IOMM ACZ1-2 ACZ 010A through 039A 27
Table 8, Fan Staging Pressures
Fan Two-Fan Unit Three-Fan Unit
Stage #1
On 150 psig, Off with unit On 150 psig, Off with unit
Stage #2
On 290 psig, Off 170 psig On 290 psig, Off 170 psig
Stage #3
On 310 psig, Off 180 psig
Note: Fan #1 is on with first compressor above 75°F (24°C).
Inputs/Outputs
Table 9, Inputs and Outputs
Analog Inputs
# Description Signal Source Range
1 Open
2 Evaporator Refrigerant Pressure 0.5 VDC to 4.5 VDC (NOTE 1) 0 to 132 psi
3 Condenser Refrigerant Pressure 0.5 VDC to 4.5 VDC (NOTE 1) 3.6to 410 psi
4 Open
5 Outside Ambient Temperature
Thermister (10k at 77°F, 25°C)
-58 to 212°F
NOTE: Value at the converter board input. Value at the converter board output is 0.1 VDC – 0.9 VDC.
Analog Outputs
# Description Output Signal Range
1-4 None
Digital Inputs
# Description Signal Signal
1 Unit OFF Switch 0 VAC (Stop) 24 VAC (Auto)
2 Remote Start/Stop 0 VAC (Stop) 24 VAC (Start)
3 Evaporator Water Flow/Air Flow Switch 0 VAC (No Flow) 24 VAC (Flow)
4 Motor Protection 0 VAC (Fault) 24 VAC (No Fault)
5 Open
6 Phase Voltage Fault 0 VAC (Fault) 24 VAC (No Fault)
7 Stage 1 Request 0 VAC (Stop) 24 VAC (Start)
8 Stage 2 Request 0 VAC (Stop) 24 VAC (Start)
Digital Outputs
# Description Load Output OFF Output ON
1 Alarm Alarm Indicator Alarm OFF Alarm ON
3 Liquid Line Solenoid Cooling OFF Cooling ON
4 Motor Control Relay #1 Starter Compressor OFF Compressor ON
5 Motor Control Relay #2 Starter Compressor OFF Compressor ON
6 Condenser Fan #1 Fan Contactor Fan OFF Fan ON
7 Condenser Fan #2 Fan Contactor Fan OFF Fan ON
8 Condenser Fan #3 Fan Contactor Fan OFF Fan ON
Setpoints
The setpoints shown in Table 10 are held in a non-volatile memory and remembered during
power off, are factory set to the Default value, and can be adjusted within the value shown
in the Range column.
The PW (password) column indicates the password level that must be entered in order to
change the setpoint. Passwords are as follows:
O = Operator [0100]
M = Manager, [2001}