Technical documentation
Rev. 02
Reactive Factor Controller CX plus
39
310
Control
ON/OFF/Hold
Starting, stopping and switching off the automatic control. The following
settings are available:
ON
:
Control is ON and works in normal operation.
OFF
:
Control is OFF and active steps are switched off one by one at 3
second intervals.
Hold
: Control is stopped and the active steps remain switched on.
If the control is set to "OFF", "PFC" and "OFF" appear alternatingly on the
display.
If the control is set to "Hold", "PFC" and "Hold" appear alternatingly on the
display.
In order to start the control, set the setting to “ON”.
NOTE
: If the step identification was switched off and if the current
transformer factor and no step size has been entered manually yet, the
control is switched off (“OFF”) and the setting is locked. The setting
remains locked until the current transformer factor is entered once and at
least one step size is entered manually. Then, the control can be switched
on again.
311
Control algorithm
1/2/3/4/5
A detailed description of the control algorithms can be found in the chapter
“Control algorithm”.
1) BEST-FIT (AUTO):
The controller works according to the "BEST-
FIT" principle (best result). This means that, before each switching
operation, the controller compares all step sizes saved in its step
database with the determined need for reactive power and always
selects the step which comes closest to the set control target. If
the controller has connected steps of the same size, the number of
switching operations is automatically distributed to these steps
either via the switching cycles or via the operating hours
(SETUP/315).
2) LIFO
: “Last IN, First OUT
”: The controller starts with step 1 and
switches on the step of the next higher number each time, if
necessary. The steps are switched off in reversed order. It is
checked individually for each step, if the switching operation is
useful. This may lead to an unprecise compensation in case of
steps of different sizes.
!
CAUTION
If the s
etting “Lock faulty steps” (SETUP/309) is deactivated,
steps which are identified as defective are not blocked
anymore. Their step type remains set to “AUTO”. Therefore, the
defective step is not skipped.
The control continuously switches the defective steps on and
immediately off again unnecessarily in the cycle of the switching
time. The next faultless steps are ignored for switch-on,
because the defective step is not blocked and thus not skipped.
Therefore, it may not be possible for the control to reach the
target COS-PHI. The switch-off of the steps is not affected by
this.
