CONTROL SETTINGS
ESC3 Controls
Operation
Temperature Control
Temperature control in the ESC3 is accomplished by com- paring the temperature reading of the case temperature probe against the temperature setpoint. The compressor out- put is used to control the temperature. If the temperature is above the temperature setpoint (L1) + the hysteresis setpoint (rd), the compressor output is turned on (subject to the con- ditions described in the compressor operation
Compressor Control
Several setpoints are available that allow the operation of the compressor output to be tailored to match individual needs.
Min On/Off Times and Minimum Cycle Time
Minimum ON/OFF compressor times can be specified, as well as a minimum time delay between compressor cycles. These parameters help prevent
Compressor Power ON Delay
The compressor power on delay
Compressor Safety Cycle
If the temp sensor fails, the ESC3 can be programmed to cycle the compressor ON for a fixed amount of time, followed by a
Fan Control
The fan output is controlled by the ESC3 based on the cur- rent operating mode (defrost, cooling, etc.) and the setpoints which affect fan operation. It may be set to run only when required based on case temperature, or it may be set to be always ON regardless of temperature. In addition to these two basic modes, you may also turn the fans OFF during defrost, specify the fan will be ON only when the compressor is running, and delay fan activation after defrost drip time.
Defrost Control
The ESC3 can control the defrost function of a case. The ESC3 executes defrost cycles at a
The ESC3 features a number of options to customize operation and termination of a defrost cycle. A defrost cycle can be terminated based on time or temperature. When termination by temperature is used, a minimum and maximum defrost time can be specified.
You may also program the ESC3 to begin a defrost cycle after
Alarm Control
The ESC3 has several alarm functions. In addition to alarms based on high and low air temperatures, it will alarm if a probe failure is detected. If you are using defrost, the ESC3 will also generate an alarm when the defrost cycle did not terminate as expected (such as when the ESC3 is programmed to terminate at a temper- ature set point and the set point was never reached).
Interface
The ESC3 features a 3 digit LED display that shows the case temperature. Alternately, the display can be config- ured to display the product temperature if a product tem- perature probe is connected. The temperature can be displayed in either °C or °F.
Three keys on the front panel provide an indication of operating status as well as allowing setpoints to be changed.
Alarm Key
The Alarm key illuminates when the controller has detect- ed an alarm condition. This key is also used to reset an alarm condition and to enter the setup mode (allowing setpoints to be changed).
Compressor Key
The Compressor key illuminates when the compressor output is on. When the ESC3 is in setup mode, this key is used to select a setpoint to be modified and to change the value of the setpoint.
Defrost Key
The Defrost key illuminates when the ESC3 is in defrost mode. Press the defrost key for 5 seconds to go into man- ual defrost mode. The key is also used in setup mode to select a setpoint to be modified and to change the value of the setpoint.
13
