pR300T Controller

CAREL’s know-how in natural refrigerant applications has led to the design of a new pRACK series control system, bringing the latest innovations in carbon dioxide refrigeration to the established reliability of a product developed for the management of refrigerating units.


pRack pR300T is the complete CAREL controller for managing centralised CO2 refrigerating units.

It is the ideal solution for multiple market requests regarding: 

  • High number of inputs and outputs for control needs
  • Innovative management algorithms for power saving
  • Compatible with the main standard control devices on the market
  • Ample integration/monitoring possibilities

The pR300T is ideal for managing carbon dioxide-based booster systems. The new pRack pR300T platform offers the market of transcritical CO2 systems a product that with continuous enhancements, allowing users to easily manage inherently complex systems:

  • Complete management of transcritical CO2 systems on one single controller
  • Use of a simple and intuitive user interface (customisable if needed)
  • Quick access to monitoring systems
  • Quick access to programming (USB host and device)
  • Safety and backup procedures
  • High flexibility (multi-board, I/O customisability)


  • Oil management (cooling-injection-separation)
  • Heat recovery (double heat exchanger and gas cooler bypass)
  • Control of the HPV valve (optimised algorithm for pressure calculation)
  • Flash valve adjustment (pressure of the receiver-safety devices connected to the HPV)
  • Restore procedures (fault synchronisation with case controller) Integration with Chillbooster (evaporative cooling system for air-cooled condensers)
  • Activation of parallel compression (auxiliary compressors for receiver pressure control)

Main functions and features:

One single controller for the complete management of a small-medium size compressor racks, including direct management of the HPV and flash gas valves: thanks to the driver for stepper expansion valves integrated into the controller, no external valve drivers need to be installed. Ultracap technology, embedded in the hardware, maximises system safety.


  • All in one: one board to manage compressors (MT&LT), gas cooler fans, HPV&RPRV, parallel compressor
  • Built-in safe EEV control and power-safe closure: direct management of both HPV and flash gas
  • Extensive flexibility: single or multi-board, configurable universal I/Os
  • Dynamic algorithms: optimal pressure, floating suction/condensing, MP optimisation

Technical specifications:

  • Three suction line management
  • Parallel compressor able to work as an MT compressor
  • Gas cooler and high pressure system control
  • Modulating ejector control
  • Optimisation of medium pressure control
  • Double heat recovery control
  • Oil distribution and oil pressure control
  • Double system synchronization
  • Safe restore via supervisory system

Applications: Transcritical CO2 compressor racks


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