Cold Start Thermal Shock Protection (Cstp); Cold Start Thermal Shock Protection - Modulating Operation - Siemens LMV50 Series Manual

Building Technologies

7.8 Cold start thermal shock protection (CSTP)

Thermal shock protection can be activated and deactivated.
A differentiation is made between modulating and multistage control.
The cold start sequence is activated when, upon startup, the actual value lies below the
ON threshold).
If thermal shock protection is activated, the manipulated variable on cold start is
increased in a stepwise fashion using the set load step (or the next stage is activated).
The output is increased as soon as the actual value exceeds the start value of the load
stage by the setpoint step.
If this switching threshold is not reached within the adjustable maximum time, heating is
automatically ensured by the next output stage. When the OFF threshold is reached,
the cold start sequence is ended to switch to normal control operation.
An active cold start thermal shock protection function is signaled via the AZL5; to check
the actual values, the normal display flashes up alternately.
Parameters: Thermal shock protection on/off
Activation value for thermal shock protection
Deactivation value for thermal shock protection
Load step (for modulating control only)
Setpoint step, modulating
Setpoint step, multistage
Max. time, modulating per step
Max. time, multistage per step
7.8.1 Cold start thermal shock protection – modulating
operation
For the output step, any output value in % can be predefined.
100% divided by the output step gives the number of possible stages.
Example:
Example: Example:
Burner OFF If the actual temperature
Actual temperature has not reached the
below ON threshold. setpoint step of 4 °C within
The burner is switched 5 minutes, a load step
on. occurs.
Figure 61: Cold start thermal shock protection – modulating operation
Basic Documentation LMV5...
7 Boiler controller / load controller
Example: Example:
If the temperature increases by 4 °C Once the shock protection deactivation
within 5 minutes, the next load step threshold of 60 °C has been reached,
occurs. cold start thermal shock protection is
ended.
Control operation is started.
ColdStartOn
ThresholdOn
ThresholdOff
StageLoad
StageStep_Mod
StageStep_Stage
MaxTmeMod
MaxTmeStage
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CC1P7550en
22.05.2018