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.