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...
The System Integrator Giants program lists the top 100 system integrators among companies listed in CFE Media's Global System Integrator Database.
Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
This eGuide illustrates solutions, applications and benefits of machine vision systems.
Learn how to increase device reliability in harsh environments and decrease unplanned system downtime.
This eGuide contains a series of articles and videos that considers theoretical and practical; immediate needs and a look into the future.
Additive manufacturing benefits; HMI and sensor tips; System integrator advice; Innovations from the industry
Robotic safety, collaboration, standards; DCS migration tips; IT/OT convergence; 2017 Control Engineering Salary and Career Survey
Integrated mobility; Artificial intelligence; Predictive motion control; Sensors and control system inputs; Asset Management; Cybersecurity
Featured articles highlight technologies that enable the Industrial Internet of Things, IIoT-related products and strategies to get data more easily to the user.
This article collection contains several articles on how automation and controls are helping human-machine interface (HMI) hardware and software advance.
This digital report will explore several aspects of how IIoT will transform manufacturing in the coming years.

Find and connect with the most suitable service provider for your unique application. Start searching the Global System Integrator Database Now!

Infrastructure for natural gas expansion; Artificial lift methods; Disruptive technology and fugitive gas emissions
Mobility as the means to offshore innovation; Preventing another Deepwater Horizon; ROVs as subsea robots; SCADA and the radio spectrum
Future of oil and gas projects; Reservoir models; The importance of SCADA to oil and gas
Automation Engineer; Wood Group
System Integrator; Cross Integrated Systems Group
Jose S. Vasquez, Jr.
Fire & Life Safety Engineer; Technip USA Inc.
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
click me