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Siemens Building Technologies Basic Documentation LMV5... CC1P7550en
HVAC Products 6 Temperature or pressure controller (internal load controller LC) 13.08.2004
Parameter: AdaptionLoad
The load controller integrated in the LMV5... is capable of identifying the controlled sys-
tem, of calculating its PID parameters based on the acquired characteristic data and of
resetting the parameters. In modulating mode, the adaption function is available for
both temperature and pressure control. In multistage mode, the PID controller is active,
so that no adaption can be made there.
Adaption can be activated in a number of ways:
1. Adaption from manual operation
a) Adaption from shutdown or standby «Burner OFF»
b) Adaption from startup or operation «Burner ON»
2. Adaption from automatic operation
a) Start of adaption from shutdown or standby
b) Start of adaption from startup or operation
During adaption of the LC, O2 trim control may not be active, since this can
considerably distort the PID parameters ascertained!
Manual operation,
shutdown or standby
Manual operation,
startup or operation
Automatic operation,
shutdown or standby
Automatic operation,
startup or operation
Change to automatic operation
Startup
Burner ON, low-fire Burner OFF Burner ON, low-fire
Waiting until actual value < setpoint minus 5 %
Setting phase of controlled system, fixed at 5 min
Evaluation of development of actual value. If actual value changes excessively,
setting phase will be extended by another 5 min max
Startup
Saving the startup values and output of the parameterized adaption load
When the temperature or pressure increase changes to a straight line, the delay time Tu
and the maximum increase of the controlled system is ascertained from the measured
values and the start values. These values are then used to calculate the control parameters.
If the adaption load is below 100 %, a correction factor will be used.
Adaption will be terminated or stopped:
- before the setpoint is reached
- in the case of unusual developments of the actual value (e.g. pure dead time member
with extensive dead time)
End of adaption is communicated to the AZL... . If adaption was correct, the control parameters
will be saved in EEPROM. Otherwise, the former control parameters are reinstaled and the
change to modulating control will take place.
Note:
If adaption was successful, the former control parameters in EEPROM will be overwritten.
The control then uses the new parameters without waiting for an extra confirmation by the
user. The new control parameters appear on the AZL... and are valid from now on.
Burner OFF
7550f21E/0502
Refer to chapter «Displays and settings» / special function adaption LC
Self-setting of control
parameters (adaption)
Adaption sequence
Note
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