CV_CLG_CTL Cooling Valve’s Cooling Control - Operation Manual - ELC.E14 - EM1.8D - EM1.8R - EM1.8U

Description

This function block set is mainly used to control an analog cooling valve. In a four-pipe air conditioning unit coil application, when cold water passes through the independent cooling coil, the cooling valve adjusts output proportionally according to the current temperature value and setpoint.

Of all the inputs, Fault Alarm is generated from a PID-adjustable primary sensor. Once there is such an alarm, the PID function block outputs 0%.

This set also has a manually override function. If "Cooling Valve Mode Select" is "0 - MAN (manual)", the output is "Cooling Valve Manual Setpoint". If "Cooling Valve Mode Select" is "1 - AUTO", the output is the automatic logic value of the application.

Function

When "Fan Command" is "1" (0-OFF/1-ON) and "Sensor Fault Alarm" is "0" (0-OK/1-FLT), "Cooling Valve Adjustment Control" is calculated based on PI direct proportion, ranging from 0 % to "Maximum Output".

At any time when "Cooling Valve Mode Select" is "0" (0-MAN/1-Auto), "Cooling Valve Adjustment Control" is "Valve Manual Setpoint".

When "Fan Command" is "0" (0-OFF/1-ON) or "Sensor Fault Alarm" is "1" (0-OK/1-FLT), "Cooling Valve Adjustment Control" is 0 %.

The output priority is: Manual mode > Sensor Fault Alarm > Normal PID calculation output in automatic mode.

Internal logic

Input

Output

Example