Schneider Electric 4000 Unbalance Voltage, Phase Loss-Current, Phase Loss-Voltage, Reverse Power

Chapter 6—Alarms	63230-300-212
Setpoint-Controlled Relay Functions	April 2001

Unbalance Voltage:

Pickup and dropout setpoints are entered in tenths of percent, based on the percentage difference between each phase voltage with respect to the aver- age of all phase voltages. For example, enter an unbalance of 7% as 70. The unbalance voltage alarm occurs when the phase voltage deviates from the average of the phase voltages, by the percentage pickup setpoint, for the specified pickup delay. The alarm clears when the percentage difference between the phase voltage and the average of all phases remains below the dropout setpoint for the specified dropout delay (in seconds).

Phase Loss—Current:

Pickup and dropout setpoints are entered in amperes. The phase loss current alarm occurs when any current value (but not all current values) is equal to or below the pickup setpoint for the specified pickup delay (in seconds). The alarm clears when one of the following is true:

•All of the phases remain above the dropout setpoint for the specified dropout delay, or

•All of the phases drop below the phase loss pickup setpoint.

If all of the phase currents are equal to or below the pickup setpoint, during the pickup delay, the phase loss alarm will not activate. This is considered an under current condition. It should be handled by configuring the under current protective functions.

Phase Loss—Voltage:

Pickup and dropout setpoints are entered in volts. The phase loss voltage alarm occurs when any voltage value (but not all voltage values) is equal to or below the pickup setpoint for the specified pickup delay (in seconds). The alarm clears when one of the following is true:

•All of the phases remain above the dropout setpoint for the specified dropout delay (in seconds), OR

•All of the phases drop below the phase loss pickup setpoint.

If all of the phase voltages are equal to or below the pickup setpoint, during the pickup delay, the phase loss alarm will not activate. This is considered an under voltage condition. It should be handled by configuring the under voltage protective functions.

Reverse Power:

Pickup and dropout setpoints are entered in kilowatts or kVARs. The reverse power alarm occurs when the power flows in a negative direction and remains at or below the negative pickup value for the specified pickup delay (in seconds). The alarm clears when the power reading remains above the dropout setpoint for the specified dropout delay (in seconds).

Phase Reversal:

Pickup and dropout setpoints and delays do not apply to phase reversal. The phase reversal alarm occurs when the phase voltage rotation differs from the default phase rotation. The circuit monitor assumes that an ABC phase rotation is normal. If a CBA phase rotation is normal, the user must change the circuit monitor’s phase rotation from ABC (default) to CBA. To change the phase rotation from the display, from the main menu select Setup > Meter > Advanced. For more information about changing the phase rotation setting of the circuit monitor, refer to “Advanced Meter Setup” on page 34.

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