GE PQMII, Инструкция по эксплуатации

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CHAPTER 5: SETPOINTS
PQMII POWER QUALITY METER – INSTRUCTION MANUAL 5–37
• PHASES REQ’D FOR U/V OPERATION : Select the minimum number of phases on which
the undervoltage condition must be detected before the selected output relay will
operate. This setpoint is not visible if
VT WIRING
is set to “Single Phase Direct”.
• DETECT UNDERVOLTAGE BELOW 20V : If an indication is required for loss of voltage,
select “Yes”. If “No” is selected and any one of the voltage inputs has less than 20 V
applied, the undervoltage feature will be disabled.
• OVERVOLTAGE RELAY : Overvoltage can either be disabled, used as an alarm, or as a
process control. Set this setpoint to “Off” if the feature is not required. Selecting
“Alarm” activates the alarm relay and displays an alarm message whenever an
overvoltage condition exists. Selecting an auxiliary relay activates the auxiliary relay
for an overvoltage condition but no message will be displayed. This is intended for
process control.
• OVERVOLTAGE LEVEL : When the voltage on one, two, or three phases equals or
exceeds the level determined with this setpoint, an overvoltage condition occurs. The
required number of phases is determined by the
PHASES REQUIRED FOR O/V OPERATION
setpoint. To clear the overvoltage condition, the level must decrease to 97% of the
OVERVOLTAGE LEVEL
setting. For example, if the
OVERVOLTAGE LEVEL
is set to “4200 V”, the
condition clears when the voltage in the appropriate phase(s) goes below 4074 V
(4200
×
0.97). This hysteresis is implemented to avoid nuisance alarms due to voltage
fluctuations.
• OVERVOLTAGE DELAY : If the voltage equals or exceeds the
OVERVOLTAGE LEVEL
setpoint
value for the time delay programmed in this setpoint, an overvoltage condition will
occur.
• PHASES REQ’D FOR O/V OPERATION : Select the minimum number of phases on which
the overvoltage condition must be detected before the selected output relay operates.
This setpoint is not visible if
VT WIRING
is set to “Single Phase Direct”.
• CURRENT UNBALANCE RELAY : Current unbalance is calculated as the maximum
deviation from the average divided by the average three phase current. Current
unbalance can either be disabled, used as an alarm, or as a process control. Set this
setpoint to “Off” if the feature is not required. Selecting “Alarm” activates the alarm
relay and displays an alarm message whenever a current unbalance condition exists.
Selecting an auxiliary relay activates the auxiliary relay for a current unbalance
condition but no message will be displayed. This is intended for process control.
• CURRENT UNBALANCE LEVEL : When the current unbalance equals or exceeds this
level, a current unbalance condition will occur. See 6.2.1 Current Metering for details on
the method of calculation.
• CURRENT UNBALANCE DELAY : If the current unbalance equals or exceeds the
CURRENT UNBALANCE LEVEL
value for the time delay programmed in this setpoint, a
current unbalance condition occurs.
• VOLTAGE UNBALANCE RELAY : Voltage unbalance is calculated as the maximum
deviation from the average divided by the average three phase voltage. Voltage
unbalance can either be disabled, used as an alarm, or as a process control. Set this
setpoint to “Off” if the feature is not required. Selecting “Alarm” activates the alarm
relay and displays an alarm message whenever a voltage unbalance condition exists.
Selecting an auxiliary relay activates the auxiliary relay for a voltage unbalance
condition but no message will be displayed. This is intended for process control.