NEWS | June 28, 2021

Fundamentals of Transformer Differential Protective Relay Testing

NETA Live Webinar Series presented by AVO Training Institute

The NETA Live Webinar Series is a collection of association-approved virtual training presentations sponsored by industry partners and eligible for 1 NETA CTD credit.

Each one-hour webinar will be presented live, but will also be made available for viewing on-demand through the NETA Bookstore.

These NETA webinars will cover a variety of relevant topics, are available free of charge to NETA Accredited Companies, and are also made available for purchase by Alliance Partners ($75) and Non-Members ($99).

NETA Live Webinar Series: Fundamentals of Transformer Differential Protective Relay Testing presented by AVO Training Institute
Fundamentals of Transformer Differential Protective Relay Testing
JUNE 29, 2021 | 11:00 AM EST

Differential Transformer Protection is a vastly covered topic and discussion; however, many presentations and iterations focus in on the technology and lack a practical approach.

The goal for this webinar presentation is an interactive learning experience for all attendants that will cover the fundamentals of transformer differential protection that are found in the majority of applications.

The presentation will establish the ground work of current transformer installation methods (polarity, ratio, and rating); slope; inrush current; and harmonic restraint elements.

During the live broadcast, an electromechanical relay will be utilized to visually demonstrate and support the theory behind protection; this will provide an upfront view of exactly how modern microprocessor relays have provided a foundation to improve upon by their predecessors.


Ralph Parrett is a United States Navy veteran with over 14 years of professional experience relating to electrical safety and maintenance training.

During his time at AVO Training Institute, his proven dedication to training led to his position as Manager of Content & Delivery.

His passion has always been to provide a topnotch training experience to ensure his students are more effective and safer when they return to the workplace.
Ralph has extensive knowledge of maintenance, repair, and troubleshooting of control and instrumentation, relay logic systems, ABB control systems, central control station programs, power system equipment testing and maintenance, and other various types of equipment.

He has developed and taught theory, operation, maintenance, and safety of various engineering systems.