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Phase-sequence Phase-loss Relay


Three-phase Phase-sequence Phase-loss Relay Using Voltage Detection Method. 22.5 mm (W). Two SPDT output relays


Rated input voltage 3-phase, 200 to 480 VAC (3-wire)
Input load Approx. 4.1 VA
Operating time Phase sequence 0.1 s±0.05 s
Phase loss 0.1 s max. (when the voltage changes rapidly from 100% to 0% of rated voltage)
Reset method Automatic reset
Indicators Power (PWR): Green, Relay output (RY): Yellow
Output relays One DPDT relay (NC operation)
Output relay ratings Rated load
Resistive load
5 A at 250 VAC
5 A at 30 VDC
Minimum load: 24 VDC, 4 mA (reference values)
Mechanical life: 10 million operations min.
Electrical life:
5 A at 250 VAC or 30 VDC: 50,000 operations
3 A at 250 VAC/30 VDC:100,000 operations
1 A, cos θ = 0.4 at 250 VAC: 100,000 operations
0.2 A, L/R = 100 ms at 48 VDC: 12,000 operations
Recommended fuse: NT00-6A
Rated operating voltage (Ue)
Rated operating current (Ie)
AC-12 Ue:250VAC, Ie:5 A
AC-15 Ue:250VAC, Ie:1 A
DC-12 Ue:30VDC, Ie:5 A
DC-13 Ue:24VDC, Ie:0.9 A
DC-13 Ue:48VDC, Ie:0.2 A
DC-13 Ue:24VDC, Ie:0.05 A
Ambient operating temperature -20 to 60°C (with no condensation or icing)
Storage temperature -25 to 65°C (with no condensation or icing)
Ambient operating humidity 25% to 85% (with no condensation)
Storage humidity 25% to 85% (with no condensation)
Altitude 2,000 m max.
Terminal screw tightening torque 0.49 to 0.59 N·m
Terminal wiring method Recommended wire
Solid wire: 2.5 mm2
Twisted wires: AWG16, AWG18
Note: 1. Ferrules with insulating sleeves must be used with twisted wires.
Note: 2. Two wires can be twisted together.
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
Case color N1.5
Case material PC and ABS, UL 94 V-0
Weight Approx. 130 g
Mounting Mounts to DIN Track.
Dimensions 22.5 × 90 × 100 mm (W×H×D)


Allowable operating voltage range 85% to 110% of rated input voltage
Input voltage range 200 to 480 VAC
Input frequency 50/60 Hz (no presumed range)
Overload capacity Continuous 528 V
Phase loss detection level 80%±10% of rated input
Calculation Formula
= 1 - ((Highest phase-to-phase voltage - Lowest phase-to-phase voltage)/
Average three-phase phase-to-phase voltage)
Conforming standards EN 60947-5-1
Installation environment (pollution level 2, installation category III)
EMC EN 60947-5-1
Safety standards UL 508 (Recognition), Korean Radio Waves Act (Act 10564),
CSA: C22.2 No.14, CCC: GB/T 14048.5
Insulation resistance 20 MΩ min.
Between external terminals and case
Between input terminals and output terminals
Rated insulation voltage 690 V
Dielectric strength 2,000 VAC for one minute
Between external terminals and case
Between input terminals and output terminals
Rated impulse withstand voltage 6 kV
Noise immunity 1,500 V power supply terminal common/normal mode
Square-wave noise of ±1 μs/100 ns pulse width with 1-ns rise time
Vibration resistance Frequency: 10 to 55 Hz, 0.35-mm single amplitude
10 sweeps of 5 min each in X,Y, and Z directions
Shock resistance 100 m/s2, 3 times each in 6 directions along 3 axes
Degree of protection IP40 (Terminals: IP20)
Conditional short-circuit current 1,000 A

Relationship of Mounting Distance between K8AK-PH Relays and Ambient Temperature (Reference Values)

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

K8AK-PH Specifications 3