Operation Indicators - Omron K8AB-PM Series Manual

Connections
■ Wiring Diagram
Overvoltage/Undervoltage and Phase Sequence/Phase Loss Operation Diagram
Overvoltage
setting value
L1
L2
Input
L3
Undervoltage setting value
Overvoltage alarm indicator
Flashing
Undervoltage alarm indicator
Overvoltage relay
Undervoltage relay
T1: Power ON lock (1 s or 5 s)
T1
Phase loss operation
L1
Input L2
L3
Undervoltage alarm indicator
Undervoltage relay
Note: 1. The K8AB-PM output relay is normally operative.
2. The power ON lock prevents unnecessary alarms from being generated during the
instable period when the power is first turned on. There is no relay output during timer
operation.
3. Phase loss is detected by L1, L2, and L3 voltage drops.
A phase loss will exist if any of the phases drops below 60% of the rated input.
4. L1 and L2 function both as the power supply terminals and as input terminals. If the
voltage drops dramatically, then the Relay will not operate due to an undervoltage.
5. Phase loss on the power supply or load side cannot be detected in the motor load
during operation.
4
Three-phase Phase-sequence Phase-loss Relay
Hysteresis: Fixed at 5%
Hysteresis: Fixed at 5%
Flashing
Lit
T T: Operating time (0.1 to 30 s)
Lit
T: Operating time (0.1 to 30 s)
T
Phase sequence operation
L1 L3 L1
L3 L2 L2
L2 L1 L3
Flashing Flashing
N L1 L2 L3
Voltage input
Signal output
Signal output
Load

Operation Indicators

Item Display
Ry_LED Over_LED Under_LED Over_Ry Under_Ry
Over- ON ON
voltage
Under- ON OFF
voltage
Phase OFF OFF (See
loss note 1.)
Re- ON OFF
versed
phase
Correct ON OFF
phase
Note: 1. While phase loss is detected, Over_Ry will also be OFF.
2. The indicator flashes at 1-second intervals when reversed
phases are detected and at 0.5-second intervals during the
detection time.
K8AB-PM
L1
L2 N
L3
14
11
12
Overvoltage
24
21
22
Undervoltage
Phase loss,
reversed phase
Contact operation
OFF OFF ON
ON ON OFF
ON OFF OFF
(See note
1.)
Flashing ON OFF
(See note
2.)
OFF ON ON
Cat. No. N146-E1-02