Siemens LMV51 Series Basic Documentation page 132

Menu level 1 Menu level 2
Params & Display
LoadController
Diagram
Cold start thermal shock
protection (CSTP)
Description
Example
Parameters:
132/157
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HVAC Products
Menu level 3
ControllerParam
SD_ModOff
W
SD_ModOn
R=ON
Y=OPEN
Y=CLOSED
When the cold start thermal protection has been activated, a boiler - after having dropped
below a predefined switch-on threshold - will be heated up in multistage operation.
This approach ensures that when cold, the boiler does not have to satisfy the maximum
demand for heat within a very short period of time. Thermal strain on the boiler will thus
be prevented.
The cold start sequence will be activated when, on startup, the actual value lies below
the switch-on threshold. When cold start thermal shock protection is activated, the
manipulated variable - on cold start - will be increased in a stepwise fashion using the
adjusted otuput step (or the next stage will be switched on).
Start output for the cold start is the minimum load. The increase of the output by the
output step depends on 2 criteria:
1. If the predefined change of the actual value is not reached with the current output
(setpoint step modulating or setpoint step multistage), the output will be increased by
this step (output step) when the maximum time has elapsed.
2. If the predefined change of the actual value is reached with the current output within
the maximum time, the output will be increased by one output step.
When the switch-off threshold is reached, the cold start sequence will be terminated and
normal control operation started.
Modulating burner with pressure control
For the output step, any output value in % can be predefined. 100 % divided by the
output step gives the number of possible steps.
Shock protection on / off
Shock protection activation level
Output step (only for modulating
operation)
Setpoint step moduating
Max. time modulating per step
Shock protection deactivation level
Basic Documentation LMV51...
7 Commissioning instructions for the LMV51... system
Menu level 4
SD_ModOn
SD_ModOff
Setpoint Actual value
ColdStartOn
ThresholdOn
StageLoad
StageStep_Mod
MaxTmeMod
ThresholdOff
Menu level 5 Menu level 6
7550f07E/0502
activated
40 % of setpoint
10 % of burner output
10 % of setpoint
5 minutes
80 % of setpoint
CC1P7550en
29.05.2002