BAC_AC_SumNgtCol_01

Functional description

The template BAC_AC_SumNgtCol_01 is used for night cooling with cool outside air of rooms that were warmed up during the previous day. The summer night cooling function serves to improve the quality of the air and to save electrical energy. Electrical energy for cooling is saved during the first hours of the next summer day.

Interface

BAC_AC_SumNgtCol_01 1:

System diagram

Block diagram

VAR_INPUT

rRmT       : REAL;
rSp    : REAL;

rRmT: Measured value room temperature

rSp: Set value room temperature

VAR_OUTPUT

bNgtCol    : BOOL;

bNgtCol: Summer night cooling active

VAR CONSTANT

PLT_NUM    : BYTE := 1;

PLT_NUM: all alarms and events of all plant components within a controller are included in a global alarm and event list. The assignment of events and alarms to a plant is defined by the assignment of a PLT_NUM plant number.
The recording and processing of an alarm from an aggregate or a device takes place within the templates by means of the alarm function block FB_BA_Alarm.
The evaluation of the alarms of a plant, e.g. for the generation of a collective message or for plant shutdown in case of relevant faults, takes place within the template BAC_PltAlm_01 by means of the function block FB_BA_AlarmPlt.
The evaluation of different plant events within the templates of a plant, takes place within the template BAC_PltComnMsg_01 by means of the function block FB_BA_ComnMsg.

Important! The assignment and evaluation of the alarms and events of a plant can only be done correctly if all templates of a plant have the same plant number!

The plant number can be assigned in the Project Builder in the parameter menu for the templates or via a column in the Excel import.

Program description

Instance	Type	Task
RmTHys	FB_BACnetAVSetpoint	Input of a hysteresis value around the room temperature set value. Avoids excessive switching on and off with fluctuating room temperature. The switch-on point is exceeded if the room temperature rRmT is greater than SpRm + RmTHys. The switch-off point is reached if the room temperature falls below SpRm.
Sched	FB_BACnetSchedB1201	The schedule object can be used to define periods in which night cooling is enabled.
WthTLoLmt	FB_BACnetAVSetpoint	Input value for the lower outside temperature limit. The lower outside temperature limit prevents excessive cooling.
SwiOffDiffT	FB_BACnetAVSetpoint	Input value for the difference between the room temperature and the outside temperature, from which summer night cooling is disabled.
SwiOnDiffT	FB_BACnetAVSetpoint	Input value for the difference between the room temperature and the outside temperature, from which summer night cooling is enabled.
NgtColFnct	FB_BA_NgtCol	The function block NgtColFnct is the core of the templates BAC_AC_SumNgtCol_01 and includes the actual control process of the night cooling program
NgtCol	FB_BACnetBV1204, FB_BACnetBVDisplay	The BV object indicates that night cooling is active.

Version history

Version number	Comments
1.0.1	First release