Control relay setup
27
In such cases the target power factor should
be set with a small zero preceding the decimal
point (see Figure 9).
The target power factor always forms the
upper limit of the control band. However,
a capacitive power factor in this case is
prefered to even small amounts of inductive
reactive power. So the control band is
completely within the capacitive range for the
mode of regenerative power.
4.2 Overcurrent switch off -2-
The control relay is capable of calculating
the ratio between the rms current and the
fundamental wave current (50 - 60 Hz) in the
capacitor. This is achieved using the curve of
the voltage signal.
If the set value of this ratio is exceeded
for at least one minute due to harmonic
oscillations and resulting resonance-related
amplications, then the control relay switches
off all activated stages. An alarm signal is
emitted at the same time.
After the overcurrent falls below the limiting
value, the control relay begins to activate the
stages again after waiting about 5 minutes.
Note:
This function should be set to OFF when
choked capacitor stages are used.
4.3 Switching contact as alarm contact -3-
Contact 6 of the RM 2106 device or contact
12 of the RM 2112 device can be used to issue
alarm signals.
If this menu item is set to On, then every alarm
displayed by the alarm LED will also cause
contact 6 or 12 to close.
Important information:
All contact outputs don’t have oating poten-
tial.
If a oating potential contact is required,
use an additional contactor relay.
Historical alarms (alarms that are not
pending at present) are not reported at the
alarm contact.
In addition, at setup code -3- the alarm „Target
power factor not reached“ E5 can be permitted
or suppressed. If the ind LED lights up the alarm
is permitted. Otherwise the alarm is suppressed.
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