Directional overcurrent ground relays (CRQ, IRD, IRP, IRQ, IRV, KRC, KRD, KRP, KRQ, KRT)

CRQ directional overcurrent relay

This relay provides overcurrent ground detection. The directional unit operates on negative sequence current and voltage and the overcurrent unit operates on residual or ground current.

IRD directional overcurrent ground relays

These relays are ground directional overcurrent relays which are used for the protection of transmission lines and feeder circuits. Both the time overcurrent and instantaneous overcurrent units are directionally controlled.

IRP directional overcurrent ground relays

These relays are ground directional overcurrent relays which are used for the protection of transmission lines and feeder circuits. Both the time overcurrent and instantaneous overcurrent units are directionally controlled.

KRC residual current relay

The KRC relay is current polarized. Maximum torque on the directional unit occurs when the operating current leads the polarizing current by approximately 40°

KRD residual current & voltage relay

The KRD relay is dual polarized. It utilizes the current polarized directional unit of KRC and the potential polarized unit of the KRP relay.

KRP residual voltage relay

The KRP relay is potential polarized. It has its maximum torque when the residual current lags the polarizing voltage by approximately 60°.

KRT directional round and timer relay

The KRT relay is a dual polarized high speed, directional ground relay with a static two step timer. It is used in the KDXG ground reactance switched zone scheme. It provides directional supervision of all tripping and controls the switching of the KDXG from its zone setting to zone 2 and finally to zone 3.

 Why ABB?

  • Long production life, ease of application and reliable protection
  • High quality design
  • 12 year warranty
  • Short lead times
  • Consistent on-time delivery
  • 24/7 customer support

Are you looking for support or purchase information?

Loading documents

Related offering

Select region / language