Setting Of Conditions For Voltage Sag Detection; Voltage Sag History - Omron KE1 User Manual

 Setting of conditions for voltage sag detection
If a measured voltage continues to be lower than the sag detection voltage for the specified voltage
sag duration or more, voltage sag is determined. Within 5 ms after the determination, ALM lights up
and output from the output terminal is produced.
[Setting items]
Voltage sag backup:
Voltage sag detection function:
Voltage sag detection voltage:
Voltage sag duration:
• If the power supply voltage is ensured by UPS or another device, set the voltage sag
backup setting to ON.
• Voltage sag detection is determined by measured voltages without being affected by the
VT ratio setting.
* Set each item in KM1/KE1-Setting.
* If sag detection voltage is set to 0 V, detection for 0 V may be unavailable due to the effect
of surrounding environment. Setting a value within the rated input voltage range is
recommended.
* When the voltage sag backup setting is set to OFF, the maximum setting of voltage sag
duration is 0.2 s.
If time longer than 0.2 s is set, the value is automatically overwritten with 0.2 s.
 Voltage sag history
When voltage sag is detected, the following data is automatically stored as voltage sag history:
Voltage sag occurrence time, voltage sag duration, root mean square (RMS) value (voltage), and
AD value (voltage).
As the values measured around the occurrence of voltage sag are stored as root mean square
value and AD value, voltage change at the occurrence of a voltage sag can be checked.
A/D value
(Conversion into
RMS value)
At intervals of about
0.63 ms
50 Hz
80 pieces
About 0.05 s
At intervals of about
0.52 ms
60 Hz
80 pieces
About 0.04 s
• Regarding the values measured before and after a voltage sag, the number of values to
be stored changes according to frequency.
• The data of the past eight voltage sags can be stored as history. If more voltage sags
occur, history data are deleted in chronological order to ensure storage space.
* If multiple voltages are monitored, A/D value is stored only for the first voltage sag.
* To calculate A/D value and RMS value before/after voltage sag, measured values are
obtained on the basis of the timing at which internal voltage sag detection is determined.
Accordingly, the number of measured values available before/after voltage sag may vary.
3-3 Voltage sag (instantaneous voltage drop) detection function
OFF/ON
OFF, Vrs・Vrn, Vst・Vsn, Vtr・Vtn
0.0 to 480.0 V
0.02 to 1.00 s
Before voltage sag
RMS value
Each waveform Average of 10
waveforms
At intervals of about At intervals of about
20.0 ms 200 ms
64 pieces 120 pieces
About 1.28 s About 24 s
At intervals of about At intervals of about
16.7 ms 166 ms
64 pieces 120 pieces
About 1.06 s About 20 s
(Default: OFF)
(Default: OFF)
(Default: 80.0 V)
(Default: 0.02 s)
After voltage sag
RMS value
A/D value
(Conversion into Each waveform
RMS value)
At intervals of about At intervals of about
0.63 ms 20.0 ms
80 pieces 64 pieces
About 0.05 s About 1.28 s
At intervals of about At intervals of about
0.52 ms 16.7 ms
80 pieces 64 pieces
About 0.04 s About 1.06 s
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