The three-phase monitoring/protection relay monitors phase failure/asymmetry/voltage

FKM-05/05F Microprocessor relay for phase control and sequence, for three-phase electric motor protection, 5 A, 140-300 V AC, 5-25% asymmetry, without neutral - TENSE

The phase protection relay with asymmetry adjustment is designed to protect three-phase motors sensitive to changes in line voltage asymmetry.
Device interphase voltage range: 140-300 V.

Principle of operation and adjustment

Connect the relay according to the diagram and adjust the asymmetry, fault delay, and reset time parameters based on the operating values of the load voltage.
In operating state, at normal voltage values corresponding to the adjusted asymmetry, the relay is active and the indicator LED lights up.

For models with phase sequence, it is necessary to ensure the correct phase sequence.

If the asymmetry exceeds the set value, the asymmetry fault indicator (Asm.) lights up and the relay disconnects after the set delay (DT).
When the voltage returns to normal values, the relay waits for the reset time (RT) and resumes operation.

Formula for calculating asymmetry

Asymmetry = ((Maximum Voltage - Minimum Voltage) / Maximum Voltage) × 100

Example:
((245 - 200) / 245) × 100 = 18.3%.

Technical parameters

• Operating voltage: 3×380 V AC, 50/60 Hz

• Rated auxiliary voltage: 220 V AC, 50/60 Hz (FKM-05 / 05F)

• Asymmetry range: 5-25

• Delay time (DT): 0.1-20 s

• Reset time (RT): 0.1-20 s

• Power consumption: < 6 VA

• Operating temperature: -20 °C to +55 °C

• Indication: 4 LED

• Mounting: on DIN rail

• Weight: 0.210 kg

• Switching contact: 5 A / 250 V AC (resistive load)

• Working altitude: up to 2000 m

• Cable cross-section: 2.5 mm².