SUPERV I S ION AND CONNECT I V I T Y
5/23
The first step towards better Power Quality: measurement
Referring to the voltage sag ambit, as an example, the Network Analyzer function has the ability to control three kinds of sag classes, defined by the user:
A Power Quality monitor is the most commonly used tool for detecting voltage sags and power quality issues. Measurement is the first step for checking the status of the installation and initiat- ing the root cause analysis. Power Quality measure- ments and related instrumentation are described in specific industrial Standards such as IEC61000-4-30 and IEEE 1250. Now Ekip Touch trip units for the Emax 2 embeds the power quality monitor in a low voltage molded case circuit- breaker. The Network Analyzer function complies with the prescriptions of IEC 61000-4-30 and IEEE 1250. The Network Analyzer function allows the user to set controls on the voltage in order to analyze the operation of the system: any time a control param- eter exceeds a preset threshold, an alarm is gener- ated. The accuracy of voltage measurements by the Emax 2 is excellent at 0.5%. The Emax 2 Network Analyzer complies with IEEE 1250-2011, Section 3 for the monitoring of the voltage value, imbalance and harmonic content, which is the equivalent of IEC61000-4-30 Class S for voltage values and im- balance and Class B for the harmonic content.
Parameter
Description
Sag Threshold (First Class) Sag Times (First Class) Sag Threshold (Second Class) Sag Times (Second Class) Sag Threshold (Third Class) Sag Times (Third Class)
This defines the first alarm threshold. It is expressed as % Un.
In the event of dropping under the first alarm threshold, this defines the time beyond which the alarm counter is increased. This defines the second alarm threshold. It is expressed as % Un. In the event of dropping under the second alarm threshold, this defines the time beyond which the alarm counter is increased. This defines the third alarm threshold. It is expressed as % Un. In the event of dropping under the third alarm threshold, this defines the time beyond which the alarm counter is increased.
Two different types of counters for each power quality monitoring function are made available directly on the trip unit touch screen: one is a cu- mulative counter, which stores all the alarms (for ex- ample, all the voltage sags) fromthe beginning, and one is a 24h counter, that shows the alarms in the last 24 hours. With the optional communication module (Modbus, Profibus, Profinet, etc.) eight counters for each power quality monitoring function are available: one is the cumulative and the other seven are the daily counters of the last seven days of activity.
Network Analyzer Hourly average voltage value Short voltage interruption Short voltage spikes Slow voltage sags and swells
Voltage imbalance Harmonic analysis
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