Single-phase voltage relay, window type

For monitoring over- and undervoltages simultaneously. Manual resetting and automatic resetting are supported by one relay. Separate settings and outputs are supported for over- and undervoltages. Relay warning status can easily be monitored with the LED indicator.
  • Single-phase voltage window relay
  • In 22.5 mm wide industrial housing
  • Under and over, low/low or high/high control
  • Supply voltages: 24 VAC/DC, 100 to 240 VAC
  • Easy wiring with ferrules
Specifications & ordering info

Ordering information

Measuring current

Supply voltage

Order code

1 to 10 VAC/DC,
3 to 30 VAC/DC,

15 to 150 VAC/DC



100 to 240 VAC

K8AK-VW2 100-240 VAC

20 to 200 VAC/DC,
30 to 300 VAC/DC,

60 to 600 VAC/DC

24 V AC/DC


100 to 240 VAC

K8AK-VW3 100-240 VAC


Ambient operating temperature

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

Storage temperature

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

Operating voltage range

85% to 110% of rated operating voltage

Rated power supply frequency

50/60 Hz±5 Hz (AC power supply)

Output relays
(2 × SPDT, normally closed operation)

Resistive load

5 A at 250 VAC or at 30 VDC

Maximum contact voltage

250 VAC or 30 VDC

Maximum contact current

5 A

Maximum switching capacity

1,250 VA, 150 W

Mechanical life

10,000,000 operations

Electrical life

50,000 operations at 5 A, 250 VAC or 30 VDC

Degree of protection

Terminal section: IP20

Case material

PC and ABS


Approx. 150 g

Operating power

Isolated power supply

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

(AL1 and AL2)

Operating value setting range

10% to 100% of maximum measuring voltage

Operating value

100% operation at set value

Reset (HYS.)


5% of operating value (fixed)

Resetting method

Manual reset/automatic reset (switchable)

Manual reset: Turn OFF operating power for 1 s or longer

Operating time (T)

0.1 to 30 s

Power ON lock (LOCK)

1 s or 5 s (Switched using DIP switch)


Power (PWR): Green LED, relay output (RY): Yellow LED, alarm outputs (ALM 1/2): Red LED

Repeat accuracy

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)

Input frequency

40 to 500 Hz

Overload capacity

Continuous input at 115% of maximum input, 10 s at 125% (up to 600 VAC)

Applicable standards

Conforming standards

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


EN 60947-5-1

Safety standards

UL 508 (Recognition), Korean Radio Waves Act (Act 10564), CSA and CCC

Size in mm (H × W × D)

90 × 22.5 × 100

Have a question?

We are ready to help.

Contact us

Download catalogue

Browse our products offline (PDF).

Get your copy

Product documentation

Download datasheets, manuals and brochures.

Browse download center

Events and fairs

See our systems in use and consult our experts.

View upcoming events