137
24-ICM326H Typical System Diagram
Mode Of Operation
Applications
• Ideal For Low Ambi-
ent Conditions.
• Found In Supermar-
kets, Frozen Food
Storage, Computer
Rooms, Cooling Tow-
er Fans, Temperature/
Humidity-sensitive
Environments.
• Head pressure controls
operate as temperature-
sensitive motor fan speed
controls. Head pressure
is regulated during low
ambient conditions by
varying the amount
of airflow through the
condenser. This helps
ensure sufficient pressure
across the expansion valve,
preventing costly down
time and or loss of valuable
perishable goods.
Dual ON/ OFF Delays Control Fan
Part #
Features & Applications
Specifications Cross Reference
24-ICM325H
120-480 VAC
• Integral heat pump bypass circuitry allows electronic
bypass of speed control.
• Eliminates overshoots common to on/ off and pressure
switch controls.
• Helps prevent evaporator freeze-ups, low pressure cut-outs
and liquid-slugged compressors in low ambient conditions.
• One model covers 120 to 480 VAC.
• Features hard start (adj. 1 to 5 sec.), low speed cut-off
(adj.), high temperature bypass, isolated 24 VAC supply.
• Controls up to 3 refrigerant circuits.
• Typical application: heat pumps.
• 4.5" × 3" × 1.75".
Input
• Control: 18-30 VAC.
• Frequency: 50/ 60
Hz. 1.8 VA max.
• Line input: 120-480
VAC.
Output
• Max: 10 amps.
• Min: 100 mA.
One ICM model
replaces:
Hoffman
• 800
• 800A
• 800AA
• 814-50
• 816-10
Ranco
• E31 Series
Johnson Controls
• P66
ACT
• FM2000
24-ICM325
120-600 VAC
• Eliminates overshoots common to on/ off and pressure
switch controls.
• One model covers 120 to 600 VAC.
• Features hard start, low temperature bypass, isolated 24
VAC supply.
• Controls one refrigerant circuit.
• Typical application: refrigeration and A/C.
• 4.5" × 3" × 1.75".
Accessories:
• 24-ICM375 probe, 50° to 80°F (10° to 27°C).
• 24-ICM376 probe, 70° to 100°F (21° to 38°C).
• 24-ICM377 probe, 95 to 120°F (35° to 49°C).
Input
• Control: 18-30 VAC.
• Frequency: 50/ 60
Hz.
• Line input: 120-600
VAC.
Output
• Max: 10 amps.
• Min: 100 mA.
N/A
24-ICM326H
120 or 208/ 240 VAC
24-ICM327H
480 VAC
• Built-in transformer eliminates cost, reduces installation
time and simplifies wiring.
• Helps prevent evaporator freeze-ups, low pressure cut-outs
and liquid-slugged compressors in low ambient conditions.
• Features hard start, low temperature cut-off, high tempera-
ture bypass.
• 4.5" × 3" × 2".
• Typical application: ideal for heat pumps, line voltage air
conditioning and refrigeration.
24-ICM326H
• Control: 120 or 208/
240 VAC.
24-ICM327H
• Control: 480 VAC.
• Frequency: 50/ 60
Hz.
Output current:
• Max: 10 amps.
• Min: 100 mA.
Hoffman
• 800
• 800A
• 800AA
• 814-50
• 816-10
Ranco
• E31 Series
Johnson Controls
• P66
Head Pressure Controls
Solid State Controls
Head Pressure Controls
