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Minimum Voltage Relay of Three-phase Current

NL-11 - minimum voltage relay of three-phase current


The NL-11 relays of minimum voltage of three-phase current with output signal delay and instantaneous contact are intended for control of simultaneous reduction of voltage in three-phase circuit of alternating current and giving out signals with time delay to protection devices and automatics upon reaching by input voltage of certain preset level.

Operating conditions: closed production facilities located in areas with mild and cold climate (UHL-version), with tropical climate (T-version).

The range of working temperatures: from minus 40 to plus 55 ºС.

Rated AC line voltage (Urated) with a frequency of 50 Hz, V (according to versions) 100, 220, 380
The range of settings (according to voltage), V 40-80% Urated
The range of settings (according to time), s 0,1-1
Actuating variation (maximum), % 1
Power consumption, VА:
Urated = 110 V
Urated = 220 V
Urated = 380 V
Return coefficient 1,05 - 1,1

The relays have one change-over contact of immediate action and one change-over contact with time delay ; switching currents are from 0.2 to 3A at voltages from 24 to 250 V and at power:

  • in DC circuits: not more than 60 W at t=0.005s and not more than 30 W at t=0.02s;
  • in the AC circuits: not more than 300 VA at a power factor of cosj³0.5.

Long-term allowable contact current is 4 A.
Average lifetime of the relay is 12 years, average operating time to failure is 25000 hours.
Mechanical wear resistance of the relay is not less than 100 000 cycles, switching - not less than 20 000 cycles.

The insulation resistance of the relay between independent conductive circuits is not less:

  • 20 МОm – in cold condition when the device is received;
  • 10 МОm – in cold condition by the end of the service life;
  • 6 МОm – in the heated condition at the ambient temperature of 55 ºС;
  • 1 МОm – at the temperature of 35 ºС and relative humidity of the environment not more than 98%.

Electrical insulation is tested (at acceptance in normal climatic conditions between independent conductive circuits, as well as between independent conductive circuits and the panel on which the relay is installed) with a voltage of 2500 V.

The relays are supplied to the customer fully adjusted, and an additional control or adjustment is not required during installation.

NL-11 - relay operation diagram

Relay operation diagram

NL-11 - connection diagram

Connection diagram and
pin(s) locations

NL-11 - outside and linkage dimensions

Outside and linkage dimensions