3-phase sequence, phase-loss relay

The K8AK-PH1 monitoring relay is designed to monitor 3-phase 3-wire supplies. It simultaneously monitors phase sequence and phase loss during start up as well as phase loss during operation. The output relay releases when alarm conditions are detected, and the warning status can easily be monitored using the LED indicator. Suitable for industrial facilities and equipment.
  • Monitors phase sequence and phase-loss simultaneously
  • Measuring range: 200 to 480 VAC
  • Power supply voltage is the same as measuring voltage
  • Operation reaction time: 0.1 s maximum
Specifications & ordering info

Ordering information

Rated input voltage

Order code

200 to 480 VAC



Ambient operating temperature

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

Storage temperature

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


2,000 m max.

Input frequency

50/60 Hz (AC power supply)

Output relays

(1 × DPDT, 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, 150W

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. 130 g

Rated input voltage

Three-phase, three-wire mode, 200 to 480 VAC

Reversed phase and phase loss operating time

0.1 s max.

Resetting method

Automatic reset

Overload capacity

Continuous input: 528 VAC


Power (PWR): Green LED, relay output (RY): Yellow LED

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