POWER QUALIT Y PR ODUCT FU NCTION S
1TNC9 2825 0M0201 25
3.3.6 Voltage interruption supervision
Voltage interruption is a special case of voltage dip. It provides a second level setting in addi-
tion to voltage dip supervision to assist the operator in network analysis.
The interruption threshold and hysteresis voltage settings are a percentage of the system
rated voltage Un.
In single-phase system, when U
int
falls below the threshold, an alarm is triggered; when U
int
is
equal to or above the dip threshold plus the hysteresis, the alarm is reset.
In three-phase system, when U
int
of any phase falls below the threshold, an alarm is triggered;
The alarm is reset when U
int
of three-phase are recovered to or above the threshold plus the
hysteresis value, the alarm is reset.