[Hcl22] Electric heating coil, temperature-controlled
Program block, name / node subtype: [Hcl22] Electric heating coil, temperature-controlled
Library hierarchy: Ventilation and air conditioning equipment
Family: Hcl
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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.
Controls the supply air temperature (heating) by modulating an output signal to the electrical heater (OutItf21).
Alternatively, a request for different stages can be sent to the electrical heating coil (OutItf22).
Most likely this heating coil is used in an air handling unit. CMDSEQ_B has a setting (Feedback or Timeout) for the switching-off sequence for the position of heating coil for 1 second (optimized for a hot water heating coil). In case of an electric heating coil, set it to a value that is longer than the delay-off time for the operating state of the heating coil.
There is a delay-off time, e.g., 1 min, for the signal for the operating state that keeps its value to "True" after the heating coil becomes inactive. The operating state of the heating coil is read by CMDSEQ_B if used in an air handling unit plant (which is most likely the case). If the plant is about to be switched off and the heating coil was active, the plant runs for some time with a heating coil switched off to evacuate the heat. During the switching-off, CMDSEQ_B receives the operating state "True" for the duration of this delay and waits with the switching-off. This helps to dry the coil.
This program block has the following optional functions:
Option: Disable heating at high outside temperature
Heating is disabled above a specific outside air temperature, e.g., above 18 °C.
Delete this option if this coil is used as a reheater.
Option: Disable temperature control in case of dehumidification
Provides an interface (most likely to the cooling coil) and logic to disable the temperature control in case of dehumidification to not preheat the air when the cooling coil performs dehumidification.
Delete this option if this coil is used as a reheater.
Option: Do not generate disturbance signal switching off the plant at high outside temperature
To increase the availability of the air handling unit at high outside temperature, the generation of a disturbance signal that switches off the plant is disabled, and the plant continues running in the event of an alarm from the heating coil.
Option: Fault (1xBI)
Reads a fault contact and generates an alarm.
Option: Feedback (1xBI)
Reads the feedback signal and generates an alarm if feedback is missing when the coil must run.
Option: Flow detector (1xBI)
Reads the signal from a flow detector and releases the output interface and the control.
Option: Maintenance switch (1xBI)
Reads the signal from the maintenance switch and generates an alarm. If active, the outputs are stopped with very high priority (priority 2).
Option: Overtemperature detector (1xBI)
Reads the signal from an overtemperature detector and generates an alarm. The program logic stops the temperature control.
Option: Safety temperature limiter (1xBI)
Reads the signal from a safety temperature limiter and generates an alarm. The program logic stops the temperature control.
Name | Description | Type | Alarm / Notification class | Trend / Type |
|---|---|---|---|---|
TCtr | Temperature controller | Ctr: Controller | N/A | N/A |
OutItf | Interface output | N/A | N/A |
Name | Description | Type | Alarm / Notification class | Trend / Type |
|---|---|---|---|---|
Flt | Fault | BI: Binary input | Yes, 4/5 | No |
MntnSwi | Maintenance switch | BI: Binary input | Yes, 5 | No |
Fb | Feedback | BI: Binary input | Yes, 4 | No |
OvrTDet | Overtemperature detector | BI: Binary input | Yes, 4 | Yes, 4 |
SftyTLm | Safety temperature limiter | BI: Binary input | Yes, 5 | No |
FlDet | Flow detector | BI: Binary input | No | No |
Description |
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Disable heating at high outside temperature |
Disable temperature control in case of dehumidification |
Do not generate disturbance signal that switches off the plant only at high outside temperature. |
This module needs a running fan (there is an input pin to connect the supply fan's operating state) or a signal from a flow detector.