Master controller zero energy band @@&name@@

 

Master controller for a cascade sequence control with zero energy band, e.g. for the application as master controller of outlet air temperature.

 

The controller has to be referenced to the function "@@&ref@@", as this has all the necessary information on the status of the system (e.g. free cooling, dehumidification active, etc.)

 

Zero energy band means here that the control doesn't takes place at an exact set point of e.g. 21°C. In such a case, for example, there is always a heater or a cooler active.

 

This controller works with a temperature range, e.g. 20°C to 24°C. If this temperature range is reached, no more energy is used to adjust to an exact value. This saves energy and thus costs.

 

If the actual value is within the tolerance band, the set points of heating/cooling of the slave controller are raised or lowered until the minimum required energy input is reached to attain the limit range of the tolerance band.

 

The set points of the reference variable are to be understood as follows:

- Set point cooling: Should be cooled up to this value with the aid of the sequence controller like, for example, cooler.

- Set point heating: Should be heated up to this value with the aid of the sequence controller like, for example, heater.

 

The set points of the dependent variable are to be understood as follows:

- Set point cooling: Connect to the devices that can actively cool.

- Set point heating: Connect to the devices that can actively heat.

 

Devices that work without energy input, like WRG or mixed air, can be connected at the mean value of the set point of the dependent variable.

 

In this way, a dead band is achieved between the sequence controllers, which in addition positively influences the energy input.

The set point of the reference variable can come from a set point function (e.g. room set point) or be parameterised as a constant set point.

 

If there is no enabling of the control, the set point of the dependent variable is initialised with the set point of the reference variable. After enabling of the control, the master controller works from this point.

 

If the cooling protection is active, the maximum dependent set point is displayed. With active over-heat protection, the minimum dependent set point is displayed.

 

Parameter

Value

Unit control variable

°C

Unit dependent variable

°C

Set point preselection (0=constant, 1=Set point function)

@adj_SollwertWahl.0p@

Set point control variable heating (if constant)

@adj_SollwertHeizen.1p@

Set point control variable cooling (if constant)

@adj_SollwertKuehlen.1p@

Proportional range

@adj_P_Band.1p@

Reset time

@adj_I_Zeit.1p@ s

Differential time

@adj_D_Anteil.1p@ s

Dead band

@adj_Totzone.1p@

Scanning time of the controller

@adj_Abtasten.1p@ s

Set point dependent variable (0=Auto, 1=Manual)

@adj_YWahl.0p@

Set point dependent variable heating with manual intervention

@adj_YHandHeizen.1p@

Set point dependent variable cooling with manual intervention

@adj_YHandKuehlen.1p@

Selection minimum/maximum dependent variable (0=constant, 1=set point function)

@adj_MinMaxWahl.0p@

Minimum dependent variable

@adj_YMin.1p@

Minimum dependent variable

@adj_YMax.1p@