The RUT-1, RUT-3 relays are meant for use in the automation and protection circuits as voltage monitoring elements with a programmable time delay and hysteresis (a difference between pick up and drop out voltage). For each of the relays the following operating modes are available:

  • POD-NAP – operation after identifying decrease of monitored voltage below set value (Time-delay under-voltage protection)
  • NAD-NAP – operation after identifying increase of monitored voltage over set value (Time-delay over-voltage protection)
  • KPW – operation when monitored voltage is within a set range (Time-delay within-range protection)
  • KPZ – operation when monitored voltage is beyond a set range (Time-delay out of-range protection)

The RUT - type relay has isolated measuring inputs. RUT-3 monitors up to three independent values of effective sinusoidal voltage 50Hz, RUT-1 monitors one DC voltage. Voltage level detector checks extreme values of effective voltage measured, and the steering system executes programmed functions basing on information from the detector, and state of the input blockade.

The relay has one instantaneous changeover contact of the activation relay (PP), two time-delayed changeover contacts of the operating relay (PW), one make contact of the relay signalling activation of a blockade (PB). blokady (PB).