Siemens ACCESS 9340 Reference Manual page 85

PMCM-9340D-0208
2/2008
© 2008 Siemens Energy & Automation, Inc. All Rights Reserved.
example, enter an unbalance of 7% as 70. The unbalance current
alarm occurs when the phase current deviates from the average of
the phase currents, by the percentage pickup setpoint, for the
specified pickup delay. The alarm clears when the percentage
difference between the phase current and the average of all phases
remains below the dropout setpoint for the specified dropout delay
period.
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 average 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 alarm 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
ACCESS 9340 and 9360 Meters
Chapter 6—Basic Alarms
EN–77