consequence is that if only one or two phases are monitored, it is sufficient that
these monitored phases activate the
START
output.
10.3.4.2
Variation detection
The module compares the measured voltage against the limit settings. If there is
a permanent undervoltage or overvoltage, the
Reference voltage setting can be set
to this voltage level to avoid the undesired voltage dip or swell indications. This is
accomplished by converting the variation limits with the
Reference voltage setting
in the variation detection module, that is, when there is a voltage different from the
nominal voltage, the
Reference voltage setting is set to this voltage.
The
Variation enable setting is used for enabling or disabling the variation types.
By default, the setting value is "Swell+dip+Int" and all the alternative variation types
are indicated. For example, for setting "Swell+dip", the interruption detection is not
active and only swell or dip events are indicated.
In a case where
Phase mode is "Single Phase" and the dip functionality is available,
the output
DIPST
is activated when the measured TRMS value drops below the
Voltage dip set 3 setting in one phase and also remains above the Voltage Int set
setting. If the voltage drops below the
Voltage Int set setting, the output
INTST
is activated.
INTST
is deactivated when the voltage value rises above the setting
Voltage Int set. When the same measured TRMS magnitude rises above the setting
Voltage swell set 3, the
SWELLST
output is activated.
There are three setting value limits for dip (
Voltage dip set 1..3) and swell activation
(
Voltage swell set 1..3) and one setting value limit for interruption.
If
Phase mode is "Three Phase", the
DIPST
and
INTST
outputs are
activated when the voltage levels of all monitored phases, defined with
the parameter
Phase supervision, drop below the Voltage Int set setting
value. An example for the detection principle of voltage interruption for
"Three Phase" when
Phase supervision is "Ph A + B + C", and also the
corresponding start signals when
Phase mode is "Single Phase", are as
shown in the example for the detection of a three-phase interruption.
Power quality measurement functions
1MRS758755 C
710
REC615 & RER615
Technical Manual
