[CGenPltMod21] Plant operating mode determination for refrigeration generation
Program block, name / node subtype: [CGenPltMod21] Plant operating mode determination for refrigeration generation
Library hierarchy: Cooling and refrigeration equipment
Family: CGenPltMod
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*SttUpAlmHdl21a in controllers with system version < 1.5 |
Configurator
Program blocks are stored in the library without I/Os. Use the auto-create and auto-connect functions to create I/Os and/or to connect them to the interface blocks, e.g., R_A, CMD_B. Alternatively, take the I/Os from the folder containing the predefined I/Os in the library and/or from the plant and connect them to the interface blocks.
Determines the plant operating mode by considering various possible sources (e.g., scheduler, manual operation, room unit).
For plants with heat pumps.
Possible operating modes
Operating mode | Description |
|---|---|
Off | All aggregates are off (the heat pumps are off). |
On | All aggregates are on (the heat pumps are on). |
The operating mode is shown on BACnet with a multistate calculated value "Present operating mode" with the states "Off" and "On".
A parameter in the program is preset to prevent the plant from running. This is useful for testing data points. It must be switched off to start the plant.
"Startup function and alarm handling" controls the startup behavior of the plant after power-on. There is a delay after startup, "DlySttUp", of about 50 seconds. Do not change this delay. Change the delay, "DlyOn", so that it is different for each plant. This ensures that plants start one after another and do not overload the electrical system. There is also a collection and aggregation of all faults and alarms from the plant. If a local alarm lamp and/or reset button is required, an alternative can be selected.
This program block has the following optional functions:
Option: Emergency switch (1xBI)
Reads the signal from an emergency switch, generates an alarm, and stops the plant.
Option: External off
Interface that can be connected to a program logic for shutting down the plant.
Option: Fault expansion vessel (1xBI)
Reads the signal from the control unit of the expansion vessel, generates an alarm, and stops the plant.
Option: Fire detection contact (1xBI)
Reads the signal from the fire detection contact, generates an alarm, and stops the plant.
Option: Gas detector (1xBI)
Reads the signal from a gas detector, generates an alarm, and stops the plant.
Option: Minimum pressure (1xAI)
Reads the signal from a pressure sensor in the chilled water and compares it to the low limit for alarming. If the pressure drops below the low limit, it generates an alarm and stops the plant.
Option: Operating mode switch (1xMI=2xBI)
Reads the state of an operating mode switch, normally at the front of the electrical panel, and has the states "Auto", "Off", and "On".
Option: Operation indication (1xBO)
Commands a lamp (usually green) that turns on if the plant is running or that blinks if a switching operation is in progress.
Option: Scheduler
Scheduler of type MSCHED with the states "Off" and "On" that switches the plant off and on.
Even with two states only, this is a multistate scheduler (not binary) that can be extended more easily if the project requires it.
Option: Storage tank charge request
A parameter defines the response of the plant to a charge request from the storage tank:
- Value = 0: The storage tank charge request starts the plant independent of other requests, e.g., request from the consumers collected over the supply chain function.
- Value = 1: The storage tank charge request starts the plant only if another request, e.g., request from the consumers collected over the supply chain function, is active.
If there is no supply chain function that collects requests from the consumers, set the value to 0.
Name | Description | Type | Alarm / Notification class | Trend / Type | |
|---|---|---|---|---|---|
OpModMan | Manual operating mode selection | MCnfVal: Multistate configuration value | N/A | Yes, 4 | |
PrOpMod | Present operating mode | MCalcVal: Multistate calculated value | No | Yes, 4 | |
RsnPrOpMod | Reason for present operating mode | MCalcVal: Multistate calculated value | No | Yes, 4 | |
SttUpAlmHdl | Startup function and alarm handling | [SttUpAlmHdl22a] Startup & alarm handling, acknowledge & reset, 3 priorities | N/A | N/A | |
Name | Description | Type | Alarm / Notification class | Trend / Type | |
|---|---|---|---|---|---|
OpModSwi | Operating mode switch | MI: Multistate input | No | Yes, 4 | |
Sched | Scheduler | MSchedule: Multistate scheduler | N/A | N/A | |
OpInd | Operation indication | BO: Binary output | No | Yes, 3 | |
EmgSwi | Emergency switch | BI: Binary input | Yes, 4 | No | |
FireDetCont | Fire detection contact | BI: Binary input | Yes, 4 | No | |
GasDet | Gas detector | BI: Binary input | Yes, 4 | No | |
PMin | Minimum pressure | AI: Analog input | Yes, 4 | Yes, 3 | |
FltExpsVss | Fault expansion vessel | BI: Binary input | Yes, 5 | No | |
Description |
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Storage tank charge request |
External off |