RDM introduce the Mini Intuitive 3 SSR Pulse EEV Case Controller

Date: 10 September 2020
RDM introduce the Mini Intuitive 3 SSR Pulse EEV Case Controller

Resource Data Management (RDM) is delighted to introduce the Mini Intuitive 3 SSR Pulse EEV Case Controller. The newest addition to the Mini Intuitive range of small-format HVAC and refrigeration controllers is designed to control multi-evaporator single refrigeration cases. It can control up to three pulse electronic expansion valves (EEV). Its small-format design reduces space required for the installation as well as cost.

The controller’s base I/O can be extended with the Mini Intuitive Expansion Module which adds four solid-state relays (SSR) and eight probe inputs. The expansion module is required for the intended operation of the controller. The controller is available on its own or as a kit which features the Mini Intuitive Expansion Module.


The Mini Intuitive 3 SSR Pulse EEV Case Controller combines a single case-control for lights, fans, defrost and alarming with three separate SSR pulse EEV valve superheat control to achieve this control strategy.

The controller operates the electronic expansion valves via three control types: temperature control (EET), superheat control (EEV), or a combination of both (EEV/T). The controller contains logic for staggered modulation of EEVs during controller start-up or after defrost to reduce the impact of liquid hammer.

Two control applications – high temperature and low temperature case control – are pre-programmed for quick and easy setup. The return and discharge air temperature of each evaporator is monitored. Alarms will be triggered based on configurable over and under temperature values. Timed delays can be set for the alarms to allow for the temperatures to return to normal to prevent premature alarms.

If using superheat (EEV) control, then superheat can be calculated in a variety of ways suiting individual requirements:

  • Using evaporator temperature and suction line temperature probes only
  • A pressure transducer wired directly into the controller
  • Remote pressure on a network broadcast from an RDM network hub or direct from the rack/pack

The controller will operate five mechanical relays for fans, defrost, case lights, optional alarm and remote relay. A solid-state relay is allocated on the Mini Intuitive expansion module for pulsed anti-sweat heater output. One relay on the main controller can be operated via remote network command, such as the general purpose (GP) timer or an appropriate PLC program.


The new Mini Intuitive controller integrates seamlessly into the existing RDM suite of energy-saving features available on control system head-end DMTouch. It allows for remote defrost and case light scheduling, remote valve control, case performance monitoring, maximum operating pressure (MOP) protection and alarm monitoring, as well as rack shutdown support.


  • Temperature or superheat evaporator control using SSRs for pulse width modulation EEV control
  • Control of fans, defrost, lights and alarm relays; pulsed anti-sweat heaters relay
  • Energy-saving defrost skip algorithm
  • Optional 4-20mA evaporator pressure transducer for PT superheat calculation and control
  • Digital inputs for general fault, case clean, and defrost enable
  • Remote control options from RDM system head-end DMTouch
  • Remote evaporator pressure from a rack controller
  • MOP protection and alarm monitoring
  • Rack shutdown and recovery support
Find out more on our website about: HVAC, refrigeration, evaporator, superheat

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