POWER QUALITY
PRODUCT FUNCTIONS
1TNC928250M0201
23
3.3.4
Voltage dip supervision
Voltage dip is the condition of voltage dropping temporarily under the threshold level due to
an unexpected electrical system network disturbance. The dip threshold and hysteresis volt-
age settings are a percentage of the system rated voltage Un.
In single-phase system, when U
dip
falls below the threshold, an alarm is triggered; when U
dip
is
equal to or above the dip threshold plus the hysteresis, the alarm is reset.
In three-phase system, when U
dip
of any phase falls below the threshold, an alarm is triggered.
The alarm is reset when the U
dip
of three-phase are recovered to or above the threshold plus
the hysteresis value.
Voltage dip supervision settings
Value range
0=Disable 1=Enable
Default value
0
Threshold
Value range
5-100 %
Default value
10 %
Step value
1 %
Hysteresis
Value range
0-10 %
Default value
2 %
Step value
1 %
Do not set the voltage dip threshold below the lowest measurable limit. i.e.
minimum 29 VAC (Phase to N) or 50 VAC (Phase to Phase).
For example, in a 240 VAC single phase system, the minimum setting should
not be lower than 12 % (29 VAC/240 VAC). While in a 400 VAC 3-phase system,
the minimum setting should not be lower than 13 % (50 VAC/400 VAC).
