Valence Electrical Training Services

Can You Predict What Happens in a Permissive Over-Reaching Transfer Trip (POTT) Scheme?

The Relay Testing Handbook: End-to-End Testing covers the most common Communication-Assisted Protection Schemes including the Permissive Over-Reaching Transfer Trip (POTT) Scheme. This bonus animation shows the steps involved for a POTT trip.

End-to-end testers should understand how this scheme operates before they test it and this animation was created to help relay testers understand distance relay principles.

See if you can accurately predict what will happen at different fault locations with a Permissive Over-Reaching Transfer Trip (POTT) Scheme.

Press “What happens Next” to move through the animation.  Press “Move the Fault” to change the fault location.

Permissive Over-Reaching Transfer Trip (POTT) schemes have an inherent weakness due to their over-reaching nature.  This animation demonstrates a worst case scenario when using a POTT scheme during a sudden reversal.  Can you spot the problem?

About the Author Chris Werstiuk

Chris is an Electrical Engineering Technologist, a Journeyman Power System Electrician, and a Professional Engineer. He is also the Author of The Relay Testing Handbook series and founder of Valence Electrical Training Services. You can find out more about Chris here.

follow me on:

Leave a Comment:

Add Your Reply
Send this to a friend