Three-phase monitoring/protection relay monitors phase/asymmetry/voltage failure

Microprocessor relay FKM-05/05F for control and phase sequence, for protection of three-phase electric motor, 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.
Interphase voltage range of the device: 140-300 V.

Operating principle and setting

Connect the relay according to the diagram and set the asymmetry parameters, fault delay and reset time in accordance with the operating values of the load voltage.
In the operating state, at normal voltage values corresponding to the set asymmetry, the relay is active and the indication 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 shuts down 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 = ((Max Voltage - Min Voltage) / Max 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 LEDs

• Mounting: on DIN rail

• Weight: 0.210 kg

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

• Working altitude: up to 2000 m

• Wire cross-section: 2.5 mm²