Protective Relays – The Critical Brains Behind Your Power Distribution System

Share on facebook
Share on twitter
Share on linkedin

Protective relays exist to protect power distribution transmission lines, transformers, generators and electrical loads. Easter-Owens suggests that if your switchgear is over twenty years old, consider upgrading your present structure with in-place bussing and the installation of new state-of-the art circuit breakers and solid state relays. This offers a considerable cost savings over purchasing new switchgear systems.


The North American Electric Reliability Council (NERC) reports that the incorrect action of electric relaying protection accounted for 74 percent of all heavy failures in power distribution systems. These failures can result in extensive equipment damage and facility downtime. Additionally, internal switchgear arcs due to mislaid tools and faulty insulation add to the potential of shock, arc flash or arc blast/shock-wave, and often result in loss of limb or life. According to EC&M magazine, “protective relays are arguably the least understood component of medium voltage (MV) circuit protection”.

Request a Quote for Power Distribution Equipment.

Easter-Owens is a custom manufacturer who can get you

what you need. Have questions?

Our expertise in power distribution can ensure that your protective relaying is properly coordinated to minimize failures due to design. Between the load break side – which may include disconnectors, isolators, and circuit breakers; and the measurement side – usually current and voltage transformers; lies the brains of your power distribution system – protective relaying. The job of these devices when selectively coordinated properly, whether they are electro-magnetic or solid state, include:

  • Closing the trip circuit of a circuit breaker to isolate the faulty section.
  • Preventing subsequent faults by disconnecting the abnormally operating system from the healthy part of the system.
  • Minimizing damage to equipment and personnel by quickly disconnecting the faulty circuit.
  • Localizing the effect of the fault by through disconnection from the healthy system.
  • Increases system stability by minimizing system voltage disturbances.

If system performance is an issue, contact us to discuss how factors such as selectivity, sensitivity, or speed and time may be affecting your present system operation or request a quote and find out what type of equipment would be best for you.

Recents Posts