Protective Device Coordination — ETAP

Example for Coordination VS. Miscoordination

Perform Coordination Study

Select protective device coordination option
  • Create star view allows to graphically present the device’s behavior/response to a different level of overcurrent, the shadow curve present tripping point across different characteristics(long time, short time, instantaneous time). In star view characteristics curves for the protective devices can be graphically adjusted, just by clicking and dragging as shown below.
Graphical adjustment
  • protect zone this option shows the protective devices within the network on zones and divided to portions for example utility, transformer, load zone and create a star view for each zone separately.
  • Sequence Viewer clicking the Sequence Viewer button, displays the Sequence-of-Operation Events dialog box that provides a tabulated sequence summary list of actions for the applicable protective devices.
Sequence Viewer Report
  • Fault insertion allows us to simulate, show devices tripping sequence in case of fault happened.
  • Transformer voltage, kilovoltamperes, and impedance ratings
  • Primary and secondary winding connections
  • Connected load
  • Transformer magnetizing inrush current
  • Transformer thermal and mechanical protection curves
  • Short-circuit current available on both the primary and secondary
Breaker curve came before cables damage curve
Miscoordination
Main & branch CBs setting from Trip device page.
Change CBs setting
After changing CBS setting I use fault insertion to check devices tripping sequence.

That’s it!

  • Importance of preforming coordination study
  • What is the time current curve (TCC)
  • How to preform coordination study using ETAP
  • Coordinating transformer & cables protective devices
  • How to generate star view and adjusted it graphically or from Trip device page
  1. ETAP help, ETAP 12.6.0 software.
  2. IEEE 242 Recommended Practice for Protection and Coordination of Industrial and Commercial Power Systems.
  3. National electric code (NEC),articles 240.12,708.54.

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Aisha

Aisha

Electrical Engineer KAU 2019 👩🏻‍🎓✨