The ICM Controls ICM325A Universal Head Pressure Control is a single-phase, low ambient fan speed controller designed to regulate condenser fan operation in HVAC, air conditioning, and heat pump systems.

By adjusting fan speed in response to temperature or pressure changes, it helps maintain consistent condenser head pressure during cold weather operation.  This regulation supports efficient system performance, reduces the risk of low head pressure conditions, and helps protect compressors from operating instability.

Designed for flexible installation, the ICM325A supports 120 – 600 VAC line voltage, jumper-selectable 24 – 240 VAC control voltage, and 50/60 Hz operation, with a maximum motor output of 10 amps.

Compatible with single-phase permanent split capacitor (PSC) condenser fan motors, it accommodates two temperature sensors or two pressure sensors, including ICM386 temperature and ICM380 pressure sensors.

Integrated heat pump bypass enables full-speed condenser fan operation during heating mode, while NFC programming through the ICM OMNI App simplifies configuration and adjustments. The ICM325A maintains stable condenser fan operation across varying outdoor temperatures, supporting consistent refrigeration system performance.

ICM Controls ICM325A directly replaces ICM325HN Out Head with Heat Pump Bypass ICM327HN Out Head Pressure with Heat Pump Bypass and ICM326HNC-LF Pressure Control Low Ambient.

 

Frequently Asked Questions
 

• What is the ICM Controls ICM325A used for?
  The ICM325A is a universal low ambient head pressure controller designed to regulate condenser fan speed in HVAC, air conditioning, and heat pump systems. It helps maintain stable refrigerant head pressure when outdoor temperatures decrease, supporting consistent cooling performance and system reliability.
   
• How does the ICM325A control condenser fan speed?
  The ICM325A adjusts condenser fan motor speed based on temperature or pressure sensor readings. This regulation helps prevent excessively low condensing pressure during cold weather operation while maintaining appropriate system performance.
   
• What is the operating voltage of the ICM325A?
  The ICM325A supports a 120–600 VAC line voltage range, jumper-selectable 24–240 VAC control voltage, and 50/60 Hz operation. It supports a maximum condenser fan motor load of 10 amps.
   
• Is the ICM325A compatible with heat pump systems?
  Yes. The ICM325A includes an integrated heat pump bypass feature that enables full-speed condenser fan operation during heating mode, allowing the controller to accommodate compatible heat pump applications.
   
• What types of condenser fan motors are compatible with the ICM325A?
  The ICM325A is designed for compatible single-phase permanent split capacitor (PSC) condenser fan motors. Motor voltage, current rating, and application requirements should be verified before installation.
   
• Which temperature and pressure sensors work with the ICM325A?
  The ICM325A supports temperature-based or pressure-based fan speed regulation using compatible sensors, including ICM386 temperature sensors and ICM380 pressure sensors. The controller accommodates dual sensor inputs for supported configurations.
   
• Does the ICM325A support NFC programming?
  Yes. The ICM325A features Near Field Communication (NFC) technology for configuration through the ICM OMNI App, simplifying controller setup and adjustments.
   
• What are the benefits of using the ICM325A in low ambient conditions?
  The ICM325A helps stabilize condenser head pressure, maintain refrigerant system efficiency, and minimize operating problems associated with low outdoor temperatures. Its automatic fan speed adjustments support consistent system operation and reduce the risk of excessively low head pressure.
   
• What models does the ICM Controls ICM325A replace?
  Based on vendor-confirmed compatibility, the ICM325A directly replaces the ICM325HN Out Head with Heat Pump Bypass, ICM327HN Out Head Pressure with Heat Pump Bypass, and ICM326HNC-LF Pressure Control Low Ambient.
   
• Can the ICM325A be used for HVAC replacement and retrofit applications?
  Yes. Its universal voltage compatibility, selectable sensing options, heat pump bypass functionality, and NFC configuration capabilities make the ICM325A suitable for compatible HVAC equipment replacements and retrofits. Installation requirements and motor compatibility should be confirmed before replacing an existing controller.