Worth reading: AC motor protection

A new, concise handbook, "AC Motor Protection," by Stanley Zocholl, a masters-degree engineer with Schweitzer Engineering Laboratories (SEL), intends to reverse the observation that "too often, little attention is paid to critical ac motor protection factors.

04/22/2004


A new, concise handbook, "AC Motor Protection," by Stanley Zocholl, a masters-degree engineer with Schweitzer Engineering Laboratories (SEL), intends to reverse the observation that "too often, little attention is paid to critical ac motor protection factors. This 90-page, illustrated handbook promises to supply critical data for prevention of untimely ac motor failures.

Written for professional engineers, "AC Motor Protection" covers factors such as thermal limit curves and their relation to winding temperatures in an induction motor, which can result in premature motor and system failures that are costly and avoidable. The handbook includes a review of synchronous and induction motor principles, along with electrical, mechanical, and thermal models needed to provide proper relay protection for these motors operating under various conditions. A section of the handbook focuses on such motor protection requirements as pullout/stall protection, high-inertia starting, phase and ground protection, differential protection, running overload protection, and drive protection.

"AC motor protection presents unique requirements that are too often not met," says Zocholl. "In addition to faults and insulation failures, proper ac motor protection requires overcurrent protection against short circuits from external faults in connecting cables and from internal faults in motor windings. Plus, because ac motors are thermally rated and limited, protective relays must be applied to prevent overheating where no faults are present."

"AC Motor Protection" handbook is available now through SEL's web site , priced at $34.95, plus shipping.

—Frank J. Bartos, executive editor, Control Engineering, fbartos@reedbusiness.com





No comments
The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by...
Each year, a panel of Control Engineering editors and industry expert judges select the System Integrator of the Year Award winners.
Control Engineering Leaders Under 40 identifies and gives recognition to young engineers who...
Learn more about methods used to ensure that the integration between the safety system and the process control...
Adding industrial toughness and reliability to Ethernet eGuide
Technological advances like multiple-in-multiple-out (MIMO) transmitting and receiving
Virtualization advice: 4 ways splitting servers can help manufacturing; Efficient motion controls; Fill the brain drain; Learn from the HART Plant of the Year
Two sides to process safety: Combining human and technical factors in your program; Preparing HMI graphics for migrations; Mechatronics and safety; Engineers' Choice Awards
Detecting security breaches: Forensic invenstigations depend on knowing your networks inside and out; Wireless workers; Opening robotic control; Product exclusive: Robust encoders
The Ask Control Engineering blog covers all aspects of automation, including motors, drives, sensors, motion control, machine control, and embedded systems.
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
News and comments from Control Engineering process industries editor, Peter Welander.
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
This is a blog from the trenches – written by engineers who are implementing and upgrading control systems every day across every industry.
Anthony Baker is a fictitious aggregation of experts from Callisto Integration, providing manufacturing consulting and systems integration.
Integrator Guide

Integrator Guide

Search the online Automation Integrator Guide
 

Create New Listing

Visit the System Integrators page to view past winners of Control Engineering's System Integrator of the Year Award and learn how to enter the competition. You will also find more information on system integrators and Control System Integrators Association.

Case Study Database

Case Study Database

Get more exposure for your case study by uploading it to the Control Engineering case study database, where end-users can identify relevant solutions and explore what the experts are doing to effectively implement a variety of technology and productivity related projects.

These case studies provide examples of how knowledgeable solution providers have used technology, processes and people to create effective and successful implementations in real-world situations. Case studies can be completed by filling out a simple online form where you can outline the project title, abstract, and full story in 1500 words or less; upload photos, videos and a logo.

Click here to visit the Case Study Database and upload your case study.