800-624-3393

Walk-In Control System

An all-in-one electronic control that can combines temperature monitoring and alarming, door ajar alarm, entrapment alarm and leak detection into a single system.

Features

 

The WIC Walk-in Cooler Control System was designed to incorporate most of the control functions necessary to monitor safety conditions and control the operation of the refrigeration within a commercial walk-in cooler and freezer of a supermarket, convenience store or restaurant into a compact, simple to install package.

 

The Control utilizes the latest microprocessor technology with two row 16 character LCD back-lighted display. Plain English menu driven user interface is easy to understand and manipulate.

 

The WIC controls the following independent functions of the walk-in cooler or freezer:

 

 • Defrost (Off-Time, Electric or Hot Gas)

 

 • Temperature Control (Liquid Line Solenoid Cycling)

 

 • Fan Cycling

 

The WIC performs the following independent monitoring and alarming functions;

 

 • Door Ajar Alarming

 

 • Temperature Monitoring and Alarming

 

 • Refrigerant Gas Leak Monitoring

 

Defrost Clock

 

The WIC is an electronic control and time clock. The time clock can operate up to 12 defrost cycles per day.The defrost can be either gas, electric or off-time defrost.

 

During a defrost cycle the WIC will sequence through the following cycles as required:

 

  • Hot Gas / Electric Defrost
  •   Pumpdown Cycle
  •   Hot Gas / Electric Defrost Cycle
  •   Drip Cycle (System Idle)
  •   Fan Start Delay (Coil Freeze Delay)

 

Defrost Features

 

Automatically adjusts time for daylight savings. The WIC can be set to automatically change the clock for day light savings or can be set not to change if the facility is in states where daylight savings is not observed. The Daylight Savings Schedule is set through 2020.

 

Can schedule up to 12 defrost cycles per day.The WIC can be programmed to run up to 12 defrost cycles per day. The control will automatically space out each cycle evenly or allow the user to program the start times.

 

Gas, Electric, or Air defrosts.> The WIC can operate defrost circuits that are either Off-time, Hot Gas, or Electric. Steps that are not used can be set to 0 minutes, and the controller will skip over them to the next step.

 

Defrost Termination. Any one of the following functions will terminate the Main Defrost Cycle:

 

  • Temperature Setpoint (With the addition of a temperature sensor)
  • Clicks-On Thermodisk (Dry Contact)
  • Suction Pressure Switch (Dry Contact)
  • Time

 

Temperature Control

 

Each WIC comes with a temperature sensor for monitoring or controlling the temperature in the refrigerated room. The control monitors for both high and low alarms each having its own programmed delay when programmed. The WIC will maintain the space temperature by cycling the Liquid LIne Solenoid (LLS) based upon a Temperature Setpoint and a plus/minus differential. The WIC will open the LLS when the temperature reaches T = Setpoint minus Differential Value. The WIC will close the LLS when the temperature reaches T = Setpoint plus Differential Value.

 

Fan Cycling -- The WIC can cycle the evaporator fans once the temperature within the space is met. The WIC will also restart the fans after a setable delay to prevent stratification of the air.

 

Door Ajar Alarming

 

The WIC will activate its audible visual alarm and the System Alarm Relays if the monitored door is opened (Door Switch is closed) for more than the Door Open Alarm Delay time. When the door is opened, the display shows the duration of the door opening in hours and minutes. To monitor more than one door, connect all door switches in parallel. This alarm can be enabled/disabled in the CONFIGURATION MENU.

 

Temperature Alarming

 

The WIC can monitor the temperature in a single zone (room). The WIC will activate its audible visual alarm and the System Alarm Relays based upon the following alarm conditions:

 

    High Alarm. The room temperature must exceed the High Alarm Limit for a time period equal to or longer than the High Temp Alarm delay.

 

    Low Alarm. The room temperature must be below the Low Alarm Limit for a time period equal to or longer than the Low Temp Alarm delay.

 

Either alarm can be enabled/disabled in the CONFIGURATION MENU.

 

Refrigeration Leak Monitoring.

 

The WIC makes any refrigerated room Uniform Mechanical Code Compliant with the addition of a Sherlock Refrigerant Sensor. The WIC will activate alarms based upon two alarm levels. At the first alarm level, the WIC will activate its audible visual alarm and the Refrigerant Leak Level One Alarm Relays, activating any alarm notification system connected to the WIC. At the second alarm level, the WIC will activate its audible visual alarm and the Refrigerant Leak Level Two Alarm relays, activating additional alarm indication equipment and any additional safety procedures as required by local codes.

 

Gas Leak Sensors

 

The Sherlock Refrigerant Gas Sensor acts as an analog signal generator when connected to the Control via a discrete, three conductor cable. The sensor can be mounted up to 800 feet away in locations "where leaked refrigerant is likely to concentrate."

 

The gas sensors are available in three varieties:

 

  • Ceramic Metal Oxide Semiconductor (CMOS) or Solid State Sensor

 

  • Non-Dispersive, Pyro-Electric Infrared Sensor.

 

  • Electrochemical

 

With Temperature Controller

Clark Johnson Company, Inc.       2016