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Building Technologies Basic Documentation LMV5... CC1P7550en
18 VSD module 22.05.2018
18.1.4 Speed standardization
Since the standardized speed is difficult to adjust – but the correct adjustment has a
great impact on the control performance of the VSD module – an automatic measurement
function has been implemented.
Β
Note!
∂ The speed should be standardized in standby mode
∂ The speed is only standardized when parameter VSD is set to activated or to air
influen
∂ For speed standardization to start, both safety loop and burner flange contact
must be closed
∂ All actuators that have an impact on the amount of combustion air must be driven
during the normalization process to the prepurge position. Therefore parameterize
the actuators to air influen
When activating this function, the air actuators (all actuators parameterized for
determining the amount of air) are first driven to the prepurge position. The prepurge
position of the air actuators / actuators determining the amount of air should be adjusted
such that the damper is fully open.
This action can be watched via menu RatioControl ↑ Settings Gas or Oil ↑ Curve
Parameters.
Then, the VSD is controlled at 95%. A reserve of 5% is left, enabling the VSD module to
safely reach the 100% speed in situations where environmental conditions may change.
Once the motor speed has stabilized, that speed will be standardized. In other words, that
speed will represent 100%. It can be read using parameter StandardizedSp.
StandardizedSp should not be parameterized manually.
Β
Note!
If, based on the steps described above, the burner’s rated output cannot be reached
(the fan is controlled at 47.5 Hz), proceed as follows:
- Set the maximum frequency to 105.2% of the motor’s rated speed.
This means that at a motor frequency of 50 Hz:
Parameterize the maximum frequency of the VSD to 50 Hz
∂
1.052 = 52.6 Hz (on the
VSD)
- Then, standardize
This standardization cannot lead to motor overloads since only 95% of the maximum
control signal is delivered during standardization and the actual speed is controlled later
in operation and monitored via Safety time ratio control.
Caution!
If automatic speed standardization is activated, or if the standardized
speed is changed, the burner must be readjusted! Any change to the
standardized speed changes the assignment between the parameterized
percentages on the curves and the speed.
Parameter standard (deactivated / activated)
StandardizedSp
If oscillations occur during extensive running times, the settling time between
acceleration ramp and speed measurement can be extended to overcome the problem.
Parameter Settling Time (in x • 25 ms)
↑
value of 16 means 16
∂
25 ms = 400 ms
(0.4 s)
Standardization
Settling time
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