Standalone or maximum limitation control
Standalone control
In this case the "CoolCtrlSig" has “999” as a value in its parameter input box, the input "MinLimSensor" will be used as the control sensor. The setpoint is defined by parameter LIM-01, the proportional band by parameter LIM-02 and the integral time by parameter LIM-03. After start-up, when the plant mode equals a value of 1, 2, 4 or 5 and the "FanBeltIn" input becomes true (= 1), the standalone control starts as a P controller. After a delay equal to the I-time, the integral part will be activated.
The following diagram shows the control signal for standalone control.
Description |
Default value |
LIM-01: Limitation control setpoint |
14 °C |
LIM-02: Limitation control P-band |
10 K |
LIM-03: Limitation control I-time |
0 sec |
Minimum limit override control
In this case the "CoolCtrlSig" is connected to the cooling signal of the control strategy. The input "MinLimSensor" will be used as low limit sensor. The absolute minimum setpoint is defined by parameter LIM-01, the proportional band by parameter LIM-02 and the integral time by parameter LIM-03. After start-up, when the "PlantMode" code equals a value 1, 2, 4, 5 and the "FanBeltIn" input becomes true (= 1), the limitation control starts as a P controller. After a delay equal to the I-time, the integral part will be activated.
The following diagrams show the high limit control signal with PI- and P-control.
Description |
Default value |
LIM-01: Limitation control: setpoint |
50 °C |
LIM-02: Limitation control: P-band |
10 K |
LIM-03: Limitation control: I-time |
0 sec |
Note: If a limitation sensor is connected, the maximum of the two control signals “MinLimSensor” and "CoolCtrlSig” will be used to calculate the number of stages.