ICM Controls ICM325A Installation, Operation & Application Manual page 2

AIR CONDITIONING SYSTEM WIRING
L1 T1
Line Voltage
120-600 VAC
T2
L2
Contactor
Com
Run
Fan
Capacitor
Herm
Connect the wires from the contactor (load side), run capacitor, and the condenser
fan as shown in diagram above. If control voltage is desired, ensure the jumper is
placed on the control voltage enable input and the proper voltage (24-240 VAC) is
applied to the control voltage input. Place the temperature probe at T1/P1 and 5V and
mount the probe on a U-bend in the upper third of the condenser. If two temperature
probes are needed, wire the additional temperature probe to T2/P2 & 5V. If a pressure
transducer is used, mount the transducer on the discharge line at the service fitting.
Connect the red wire to +5V, the black wire to GND and the BWG (blue/white/green)
wire to T1/P1 input. If two pressure sensors are used, connect the black and red wires
of the additional pressure sensor to the same points as previously mentioned and
connect the BWG (blue/white/green) wire to TP2/P2. NOTE: Line one of the ICM325A
must share the same leg of power that is feeding the common of the run capacitor.
HEAT PUMP SYSTEM WIRING
L1 T1
Line Voltage
120-600 VAC
T2
L2
Contactor
Com
Run
Fan
Capacitor
Herm
Wiring of the ICM325A to a heat pump is the same as for air conditioning with the
exception of the Motor 2 output and the reversing valve input. For a heat pump, the
ICM325A Motor 2 terminal is connected to the outdoor fan relay input power terminal
(com) on the defrost board. The condenser fan common remains connected to the
normally closed terminal of the fan relay on the defrost board. Apply the reversing
valve voltage to the HP RV input in parallel with the existing reversing valve; for cool
active reversing valves a jumper will have to be placed at the HP O RV jumper posi-
tion. NOTE: Line one of the ICM325A must share the same leg of power that is feed-
ing the common of the run capacitor.
Single
Phase PSC
Fan Motor
Run
Common
Start
Place jumper to enable
the control voltage input
ENABLE
MOTOR 2
CONTROL INPUT
FULL SPEED
HP O RV
VARIABLE SPEED
T1/P1
LINE 2
T2/P2
+5V
GND
LINE 1 / MOTOR 1
120 - 600 VAC
HP RV
24-240VAC
ICM325A
MADE IN THE USA
CONTROL
INPUT
24-240VAC
24-240 VAC
Control Voltage
(optional)
Fan
Relay
COMN C
Defrost Board
Single
Phase PSC
Fan Motor
Run
Common
Start
Place jumper to enable
the control voltage input Place jumper to
enable a cool active
reversing valve at
the HP O RV input
ENABLE
MOTOR 2
CONTROL INPUT
FULL SPEED
HP O RV
VARIABLE SPEED
Temperature
T1/P1
LINE 2 T2/P2 Sensor
+5V
24-240 VAC
GND
reversing valve
LINE 1 / MOTOR 1
120 - 600 VAC
HP RV
input (heat active
24-240VAC
ICM325A
default)
MADE IN THE USA
CONTROL
INPUT
24-240VAC
24-240 VAC
Control Voltage
(optional)
TROUBLESHOOTING
Symptom
Fan overheats, over Check with the motor manufacturer to see if the motor is able
amps or runs very to be speed controlled by reducing the input voltage. Verify
rough
the motor is a single phase PSC motor.
The fan cycles from Check the Hard start setting in the App. Too much hard start
full ON to full OFF can drop pressure too quick causing a fan cycling effect.
with little or no
Lower the hard start in the App.
modulation
Should the fan cycling persist, move the probe up several
bends into the condenser to increase the sensitivity to the
Temperature
Sensor
condensing temperature.
Adjust the minimum output voltage in the App while fine
tuning the probe placement on the condenser.
The fan does not Using an AC voltmeter, measure the voltage between the 24
come on at all
VAC terminals. It should read approximately 24 volts.
Measure the line voltage between LINE 1 and LINE 2 to confirm
that line voltage is present. Check Line 1 of the ICM325A
and confirm it is connected to the same leg of power as the
common of the Run capacitor.
Remove the thermistor probe from the terminal block and
measure its resistance at ambient temperature. Compare your
reading at the appropriate temperature in Appendix B to see
if the actual resistance approximates the listed value. Next,
hold the probe in your hand and confirm that the resistance
decreases. If a pressure sensor is used, measure the DC
voltage between GND and the sensor output at BWG and
compare your reading to the expected pressure in Appendix A.
The high pressure
Move the probe further into the condenser where the
switch trips off temperature is higher. This will produce a higher fan RPM and
will decrease the head pressure.
Fine adjust the cutout and hard start settings in the App.
LED DIAGNOSTIC INDICATORS
GREEN AMBER
OFF
ON
OFF
OFF 2 Flashes
OFF 3 Flashes
APPENDIX A
PRESSURE VS. VOLTAGE
Pressure (PSIG)
15
50
100
150
200
250
300
350
400
450
515
Problem
Condition
• No voltage at L1 or L2
OFF • No control voltage when jumper is placed
• Output is off
OFF Full Speed Operation
ON Variable Speed Operation
Shorted Sensor (Temperature or Pressure)
Open Sensor (Temperature or Pressure)
APPENDIX B
TEMPERATURE VS. PROBE RESISTANCE
Voltage (VDC) °C
0.5 0° 32°
0.8 5° 41°
1.2 10° 50°
1.6 15° 59°
2.0 20° 68°
2.4 25° 77°
2.8 30° 86°
3.2 35° 95°
3.6 40° 104°
4.0 45° 113°
4.5 50° 122°
°F Resistance (KΩ)
32.7
25.4
19.9
15.7
12.5
10.0
8.1
6.5
5.3
4.4
3.6