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Communicates the total number of times the MDU Breaker has tripped from when usage
began to now.
MDU Breaker status
details
Trip frequency
Open/close
frequency
Remarks
Fault cause details
Outputs to display/over communication the fault cause when MDU Breaker is tripped.
Communicates/displays either long time delay (LTD), short time delay (STD), or instantaneous (INST).
Lower limit alarm
generated
Lower limit alarm
recovers
Upper limit alarm
generated
Upper limit alarm
recovers
Upper limit
value
Lower limit
value
Time
Time
Measurement
value
Measurement
value
4.5.2 MDU Breaker status
4.5.3 Fault causes
Upper/lower limit alarm
An alarm generation status is communicated if the electric current demand (current value of maximum phase electric
current demand) exceeds the set upper limit value or falls below the set lower limit value. (It is not output to the display.)
Sets the upper limit setting value and lower limit setting value via communication. (Cannot be set on display.)
Upper limit setting value
Sets the upper limit for the measurement value.
Sets the lower limit for the measurement value.
Lower limit setting value
Upper limit monitoring
Lower limit monitoring
Monitoring
Type
Generation
Recovery
Generation
Recovery
Alarm generation condition
Measurement value > upper limit setting value
Measurement value ≤ upper limit setting value
Measurement value < lower limit setting value
Measurement value ≥ lower limit setting value
Automatic reset. (No settings.) Automatically resets when the cause of the alarm is removed.
Alarm generation status
Shows whether an alarm has been generated.
Setting method
Alarm generation
condition
Reset method
4.5.4 Electric current demand upper/lower limit alarms
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The following internal accessory devices are required to measure the trip frequency and open/close frequency.
Measure trip frequency: “MDU transmission alarm switch”
Measure open/close frequency: “MDU transmission auxiliary switch”
Measure both trip frequency and open/close frequency: “MDU transmission alarm switch/auxiliary switch”
Communicates the total number of times the MDU Breaker has opened/closed from when
usage began to now.
4.5.5 Neutral line open phase alarm (NLA)
The alarm generation status is displayed when the line voltage ≥ rated operation overvoltage, and the duration ≥ operating time.
(It is not communicated.)
Set via communication or on the display
Set to either self-hold or automatic reset via communication or on the display.
Reset the alarm via communication or on the display.
Reset method
Self-hold
Automatic reset
Automatically resets when the cause of the alarm is removed.
Alarm details
Setting method
Reset method
Rated operation overvoltage:
Operating time:
Rated inoperative overvoltage:
Overvoltage inertia inoperative time:
135 VAC fixed (no settings)
1 s fixed (no settings)
120 VAC
0.1 s or more
This function is turned ON when the line system is set to single-phase three-wire system. (The function is turned OFF
when set to any other line system.)
Содержание NF250-HEV
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