Omron K8AK-AW1, K8AK-AW, K8AK-AW2, K8AK-AW3 Series Manual

NEW Product

Single-phase Overcurrent/Undercurrent Relay

K8AK-AW

Ideal for Current Monitoring for
Industrial Facilities and Equipment.

• Monitor for overcurrents and undercurrents simultaneously.
Separate settings and outputs supported for overcurrents and
undercurrents.

• Use commercially available CTs (CT current on secondary
side: 0 to 1 A or 0 to 5 A).

• Manual resetting and automatically resetting supported by one
Relay.

• Startup lock and operating time can be set separately.

• Two sets of SPDT output contacts, 5 A at 250 VAC (resistive
load).

• Output status can be monitored using LED indicator.

• Inputs are isolated from the power supply.

Refer to Safety Precautions on page 11.
Refer to page 10 for commonly asked questions.

For the most recent information on models that have been certified for
safety standards, refer to your OMRON website.

Ordering Information

List of Models

Setting range Power supply voltage Model

2 to 20 mA AC/DC
10 to 100 mA AC/DC
50 to 500 mA AC/DC

0.1 to 1 A AC/DC

0.5 to 5 A AC/DC

10 to 100 A AC*
20 to 200 A AC*

* The K8AK-AW3 is designed to be used in combination with an OMRON K8AC-CT200L Current Transformer (CT). (Direct input is not possible.)

Accessory (Order Separately)

●OMRON CT ●Commercially Available CTs*

Appearance Input range

24 VAC/DC K8AK-AW1 24 VAC/DC

100 to 240 VAC K8AK-AW1 100-240 VAC

24 VAC/DC K8AK-AW2 24 VAC/DC

100 to 240 VAC K8AK-AW2 100-240 VAC

24 VAC/DC K8AK-AW3 24 VAC/DC

100 to 240 VAC K8AK-AW3 100-240 VAC

10 to 100 A AC,
20 to 200 A AC

Applicable

Relay

K8AK-AW3 K8AC-CT200L

Model

Appearance CT current on secondary side

0 to 1 A AC,
0 to 5 A AC

* If you use a commercially available CT, do not exceed the overload

capacity of the K8AK-AW2.

Applicable

Relay

K8AK-AW2

1

K8AK-AW

Ratings and Specifications

Input Range

Model Range

0 to 20 mA AC/DC I1-COM

K8AK-AW1

K8AK-AW2

K8AK-AW3

*1 The range is selected using connected terminals.
*2 The K8AK-AW3 is designed to be used in combination with an OMRON K8AC-CT200L Current Transformer (CT). (Direct input is not possible.)

0 to 100 mA AC/DC I2-COM Approx. 1 Ω Direct input
0 to 500 mA AC/DC I3-COM Approx. 0.2 Ω Direct input

0 to 1 A AC/DC I1-COM

0 to 5 A AC/DC I2-COM

0 to 100 A AC I2-COM

0 to 200 A AC I3-COM --- OMRON CT

*1

Connection

terminals

Setting range Input impedance Input type Overload capacity

2 to 20 mA AC/DC
10 to 100 mA AC/DC
50 to 500 mA AC/DC

0.1 to 1 A AC/DC

0.5 to 5 A AC/DC

10 to 100 A AC
20 to 200 A AC

*2

*2

Approx. 5 Ω Direct input

Approx. 0.12 Ω
(Load: 0.5 VA)

Approx. 0.02 Ω
(Load: 1.5 VA)

--- OMRON CT

Direct input or
commercially
available CT

Continuous input at
120% of maximum input.
1 s at 150%

Continuous input at
120% with an OMRON
CT (K8AC-CT200L).
30 s at 200%
1 s at 600%
* CT capacity on primary

side.

2

Ratings

Power supply
voltage

Power consumption

Operating value setting range (SV)

Operating value

Reset value

Reset method

Operating time setting range (T)

Startup lock time setting range (LOCK)
Note: Enabled only for overcurrent

operation.

Indicators

Input impedance

Output relays

Output relay ratings

Ambient operating temperature

Storage temperature

Ambient operating humidity

Storage humidity

Altitude

Terminal screw tightening torque

Terminal wiring method

Case color

Case material

Weight

Mounting

Dimensions

Isolated power supply

K8AK-AW

24 VAC/DC
100 to 240 VAC

24 VAC/DC: 2.0 VA/1.1 W max.
100 to 240 VAC: 4.6 VA max.

10% to 100% of the maximum value of the setting range
K8AK-AW1: 2 to 20 mA AC/DC

K8AK-AW2: 0.1 to 1 A AC/DC (Compatible with commercially available CTs.)

K8AK-AW3: When used with the OMRON CT (K8AC-CT200L).

100% operation at set value

5% of operating value (fixed)

Manual reset/automatic reset (switchable)
Note: Manual reset: Turn OFF power supply for 1 s or longer.

0.1 to 30 s

0 to 30 s
(The startup lock timer starts when the input has reached approximately 30% or more of the set value.)
Note: Enabled only for overcurrent operation.

Power (PWR): Green, Relay output (RY): Yellow, Alarm outputs (ALM): Red

Refer to Input Range on previous page.

Two SPDT relay outputs (normally closed operation)

Rated load

Resistive load
5 A at 250 VAC

5 A at 30 VDC
Maximum switching capacity: 1,250 VA, 150 W
Minimum load: 5 VDC, 10 mA (reference values)
Mechanical life: 10 million operations min.
Electrical life: 5 A at 250 VAC or 30 VDC: 50,000 operations

−20 to 60°C (with no condensation or icing)

−25 to 65°C (with no condensation or icing)

25% to 85% (with no condensation)

25% to 85% (with no condensation)

2,000 m max.

0.49 to 0.59 N·m

Recommended wire

Solid wire: 2.5 mm
Twisted wires: AWG16, AWG18

Note: 1. Ferrules with insulating sleeves must be used with twisted wires.

Recommended ferrules

Al 1,5-8BK (for AWG16) manufactured by Phoenix Contact
Al 1-8RD (for AWG18) manufactured by Phoenix Contact
Al 0,75-8GY (for AWG18) manufactured by Phoenix Contact

N1.5

PC and ABS, UL 94 V-0

Approx. 150 g

Mounts to DIN Track.

22.5 × 90 × 100 mm (W×H×D)

10 to 100 mA AC/DC
50 to 500 mA AC/DC

0.5 to 5 A AC/DC (Compatible with commercially available CTs.)

10 to 100 A AC
20 to 200 A AC

3 A at 250 VAC/30 VDC: 100,000 operations

2

2. Two wires can be twisted together.

3

K8AK-AW

AW (I2 terminal)

0

10

60

50

40

30

20

51015

Distance between products d [mm]

I = 5 A

I = 3 A

I = 1 A

I = 0 A

Ambient temperature [°C]

K8AK

No.3

K8AK

No.2

K8AK

No.1

K8AK

No.4

K8AK

No.5

DIN Track Distance between products: d

Sample: K8AK-AW
Applied voltage: 240 VAC
Mounting distances: 0, 5, and 10 mm min.

Test method

●Relationship of Mounting Distance between
K8AK-AW Relays and Input Current
(Reference Values)

The following diagram shows the relationship between the mounting
distances and the input current.
If the relay is used with an input current that exceeds these values,
the temperature of the K8AK may rise and shorten the life of the
internal components.

Specifications

Allowable operating voltage range 85% to 110% of power supply voltage
Allowable operating frequency range 50/60 Hz ±5 Hz

Input frequency range

Overload capacity

Repeat accuracy

Applicable stan­dards

Insulation resistance

Dielectric strength

Noise immunity

Vibration resistance

Shock resistance 100 m/s2, 3 times each in 6 directions along 3 axes

Degree of protection Terminals: IP20

Operating value ±0.5% full scale (at 25°C and 65% humidity, rated power supply voltage, DC or 50/60 Hz sine wave input)
Operating time ±50 ms (at 25°C and 65% humidity, rated power supply voltage)

Conforming standards

EMC EN 60947-5-1

Safety standards

K8AK-AW1 and K8AK-AW2: DC input or AC input (45 to 65 Hz)
K8AK-AW3: AC input (45 to 65 Hz)

K8AK-AW1 and K8AK-AW2: Continuous input at 120% of maximum input, 1 s at 150%
K8AK-AW3: Continuous input at 120%, 30 s at 200%, and 1 s at 600% with an OMRON CT (K8AC-CT200L).
Note: CT capacity on primary side.

EN 60947-5-1
Installation environment (pollution level 2, installation category III)

UL 508 (Recognition), Korean Radio Waves Act (Act 10564), CSA: C22.2 No.14,
CCC: GB14048.5

20 MΩ min.

Between external terminals and case
Between power supply terminals and input terminals
Between power supply terminals and output terminals
Between input terminals and output terminals

2,000 VAC for one minute

Between external terminals and case
Between power supply terminals and input terminals
Between power supply terminals and output terminals
Between input terminals and output terminals

1,500 V power supply terminal common/normal mode
Square-wave noise of ±1 μs/100 ns pulse width with 1-ns rise time

Frequency: 10 to 55 Hz, 0.35-mm single amplitude
10 sweeps of 5 min each in X,Y, and Z directions

4

Connections

K8AK-AW1 100-240VAC

A B

Control Output

Relay output

250 VAC, 5 A (resistive load)
30 VDC, 5 A (resistive load)

A Current Input

AW1

Relay Output

Common

B Power Supply Voltage

100 to 240 VAC 24 VAC/DC

(No polarity)

A1 A2 I1

11 12 14

Relay Output

Common

100 mA max.

500 mA max.

20m A max.

AW2

5 A max.

1 A max.

AW3

100 A max.

CT

CT

200 A max.

21 24 22

C

I2 I3

A1

A2

A1

A2

C I2 I3 C I2 I3CI2I3

I1

I1 I1

21 24 22

11 12 14

21 22

CI2I3

11 12

Load

14

A1 A2

I1

A1

A2

24

Single-phase
power supply

Power
supply voltage

Power
supply
AC/DC

21 22

CI2I3

11 12

14

A1 A2

I1

A1

A2

CT

24

Single-phase
power supply

Load

Power
supply voltage

Power
supply
AC/DC

Terminal Diagram

K8AK-AW

Note: 1. Do not connect anything to terminals that are shaded in gray.

2. There is no polarity for the DC power supply input.

3. For the current input, you can input only from the C terminal and one other terminal.

4. Refer to Setting Ranges and Wiring Connections on the I1, I2, and I3 current input terminals.

5. Use the recommended ferrules if you use twisted wires.

6. The K8AK-AW3 is designed to be used in combination with the OMRON K8AC-CT200L Current Transformer (CT).

Wiring Example

Directly Inputting a Current Using a CT

5