IEEE C37.96-2012

This application guide presents generally accepted methods of protection for ac motors. It identifies and summarizes the functions necessary for adequate protection of motors based on type, size, and application. The recommendations in this guide are based on typical installations. Information relating to protection requirements, including microprocessor based protection systems, applications, and setting philosophy is provided to enable the reader to determine required protective functions for motor installations. Relay protection of squirrel-cage, wound rotor induction motors, and synchronous motors is presented herein. This guide also summarizes the uses of relays and devices, individually and in combination, so the user may select the necessary equipment, to obtain adequate motor protection. This guide is concerned primarily with the protection of three-phase integral horsepower motors and adjustable-speed drives where specifically indicated. This guide does not purport to detail the protective requirements of all motors in every situation. What it does provide is enough information and guidance for the user to implement adequate protection for most applications.

This guide provides users with methods and configurations (schemes) for implementing protection of AC motors. Initiating this revision, is need to cover new technology, applications, and explain further the AC motor characteristics used in setting protective relays.

Revision Standard - Inactive-Reserved. Generally accepted methods of protection for ac motors are provided. The functions necessary for adequate protection of motors based on type, size, and application are identified and summarized. The protective requirements of all motors in every situation is not purported to be detailed in this guide.