Questions And Answers - Omron K8AB-VW Series Quick Start Manual

Questions and Answers

Q
Checking Operation
Overvoltages
Gradually increase the input from 80% of the setting.
The input will equal the operating value when the input
exceeds the setting and the alarm indicator starts flashing.
Operation can be checked by the relay outputs that will start
after the operating time has passed.
Undervoltage
Gradually decrease the input from 120% of the setting and
check the operation using the same method as for
overvoltage.
Example: Overvoltage Operating Mode, Undervoltage Operating
Mode and an Operating Time of 5 s
Note: K8AB-VW@ output relays are normally operative.
Set value
Input voltage
Alarm indicator
Relay output
Connection Diagram
200 VAC
V
0 to 300 V
Variable
autotransformer
±
C 200 V
Cycle counter
Q How to Measure the Operating Time
Overvoltage
Change the input suddenly from 0% to 120% of the set
value and measure the time until the Unit operates.
Undervoltage
Change the input suddenly from 120% to 0% of the set
value and measure the time until the Unit operates.
Lit
Flashing
5 s
Input terminals
A1
Power supply
A2
Q
Operating Adjustment Knobs
Use a screwdriver to turn the knobs. There is a stopper to
prevent the knob from turning any further once it has been
turned completely to the left or right. Do not force the knob
past these limits.
Q Setting the Pre-alarm Monitoring Mode
Use the DIP switch to set the operating mode pins both to
overvoltage (SW3 ON and SW4 OFF) or both to
undervoltage (SW3 OFF and SW4 ON).
Example: Both Pins Set to Overvoltage
AL1 can be used as the pre-alarm for AL2 by
setting a smaller voltage set value for AL1 than for
AL2.
Q
Detecting Current with a Current Splitter
An example of detecting an overload is shown below.
Example: Overload detection in a distribution switch
board installed in a power substation.
DC power
SDV-SH
supply for
shunt
distribution
board
(−)
(+)
K8AB-VW
K8AB-VW
(without polarity)
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