Intelligent Protection Relays

Product Code: EUB 5.1

Intelligent Protection Relays

Product Details

Current-dependent, Overcurrent Time Relay

The security of supply in complex energy supply networks, is ensured by suitable protection relays. Various types are used, which in modern systems, are digital relays. The LN training system is therefore based on a digital inverse time relay, the parameters for which can be either set manually by controls on the front panel or by software and a PC. An internal program supervises the self-control and trip testing. The relay has three inverse current characteristics:

  • normal inverse
  • severe inverse
  • and extreme inverse.

The relay is connected via a current transformer, as is usual in practice. The relay is connected to a power switch module that is used to simulate an open-wire line. The voltage is switched on and off, via the signal to the protection relay; the voltage can also be switched, manually.

Topics covered

EUB 5.1 Current-dependent, overcurrent time relay (inverse time relay)

  • Adjusting the relay parameters, manually or with a PC
  • Recording the characteristics: Trip times in relation to the current at various range settings and time factors
  • Determining the pull-in and drop-out values
  • Measuring the resetting ratio
  • Measuring the operating time and the intrinsic consumption
  • Testing the relay tripping in conjunction with a power switch

Programmng software for digital protective relays

SELKA GmbH, Hamburg
Grindelallee 188, 20144 Hamburg / Germany
Tel.: + 49 (0) 40 343453 |  Fax: +49 (0) 40 63657075
E-Mail:   |  Internet: