FMS Fault Correction
Parameters ( P )
Aids
P13
If the respective channel is configured as continuous output, this setting can
Parameters 719 to 723
determine how rapidly this output must achieve the maximum adjustment.
The time set here, however, is only a minimum running time. Due to the
compound routine it may happen (for example, when using even slower
damper drives on another channel) that this time is clearly exceeded. This
parameter primarily serves to achieve an adjustment in the actuation
frequency converters. The value set here should agree with the run-up time
programmed on the frequency converter.
_____________________________________________________________________________________________________
P14
This defines the dead band of the load input. Load changes lying within this
Parameter 839
entered range are ignored and do not lead to any adjustment of the
compound. If the load dead band selected is too small, the compound runs
very erratically, since even the most minor load changes give rise to a
correction. Due to the additional routines, such as air advance in the event of
changes in power output and overshoot (approaching of control element from
one side) this leads to unnecessary disturbance. With a slightly fluctuating or
disturbed load signal the control elements are in constant movement.
Selecting too large a load dead band means that power requirements are not
run at full capacity by the load control unit, or that this is done only when the
set-point/actual difference becomes even greater, the change then occurring
in an abrupt surge.This can lead to excessive fluctuations in the actual value
of the control equipment (steam pressure or supply temperature). The
optimum for this parameter must be determined on the system. Only in
exceptional cases should the parameter content should be set below three
digits, however, so that at least the signal fluctuations on the load input do not
lead to adjustment of the compound
_____________________________________________________________________________________________________
P15
This setting determines the minimum running time of the compound in
Parameter 729
seconds. This parameter serves to purposely retard the run-up time of the
burner from low load to full load, or the run-down time in the opposite
direction.
_____________________________________________________________________________________________________
P16
If the respective channel is configured for DPS these parameters can be used
Parameters 730 to 734
to enter the minimum cycle length that must be emitted in the actuation of the
relay module. The electronic compound endeavours to set the necessary
cycle length for adjustment of the control element as a function of its running
time and of the steepness of the curve, so that all control elements run to the
new value as synchronously as possible. To do this it makes maximum use of
short timing pulses in order to achieve a large variance between the control
elements. Where external factors (inertia of the contactors or of the motor, or
use of mechanical relay modules) call for a minimum cycle length so as to
produce any reaction at all, this must be entered here. Where electronic relay
modules and responsive motors are used, the smallest possible cycle length
should be selected in the interests of a smooth and evenly running
compound. Where type 6 60 R 0011 mechanical relay modules are used, the
th
minimum cycle length must be set to no lower than one 1/10 of a second.
th
With cycle lengths than 1/10 of a second the relay may fail to transmit the
clock pulses. The smallest value that can be emitted is 50 ms.
_____________________________________________________________________________________________________
P17
This parameter is used to set the number of points by which the internal load
Parameter 754
must fall for the compound, during setting, to skip automatically to the
"Set/Control” mode.
111
