January 3, 2017
Shaft currents can have a destructive effect on electric motor bearings. This article, with information from our friends at AEGIS Shaft Grounding Rings, is intended to inform professionals about these voltages and their effects on bearings in electric motors. Because of the high-speed switching frequencies in PWM inverters, variable frequency drives induce shaft currents in …
December 26, 2016
Tom Spettel, Senior Reliability Engineer, Category IV ISO Certified Vibration Analyst The below video is a vibration analysis case study where there was a coupling bolt failure on a 4000HP ID Fan motor on a fluid drive. This was originally presented at the 2016 Reliability, Process, & Maintenance Symposium (RPM) in Kalamazoo, Michigan on September …
December 1, 2016
Todd A. Hatfield – Vice President of Engineering & Repair, HECO This is the second article (video) in a series of articles on The Basics of AC Induction Motors. The first video explored the basic principles of AC Induction motors focusing on magnetism, electromagnetic induction, AC current, and rotating magnetic fields. This segment discusses the …
November 21, 2016
Tom Spettel, Senior Reliability Engineer, Category IV ISO Certified Vibration Analyst The below video is a case study of a 400HP, 3600RPM (2 Pole) Boiler Feed Water Pump Motor that had vibration problems after a used motor was put in place of the original motor. This was originally presented at the 2016 Reliability, Process, & …
November 14, 2016
Todd A. Hatfield – Vice President of Engineering & Repair, HECO This is the first article (video) in a series of articles on The Basics of AC Induction Motors. This video explores the basic principles of AC Induction motors. This segment discusses magnetism basics, the law of electromagnetic induction, AC current, and the explanation of …
November 9, 2016
Tom Spettel, Senior Reliability Engineer, Category IV ISO Certified Vibration Analyst The below video is a case study of a 4000HP Induced Draft (I.D.) Fan Structural Resonance. This was originally presented at the 2016 Reliability, Process, & Maintenance Symposium (RPM) in Kalamazoo, Michigan on September 13-14, 2016.
November 1, 2016
Before reading this article – be sure to first read the first and second articles in this case study series. The results of the “on-site” findings in conjunction with the “in-shop” inspection led to the electric motor repair approval to build a new rotor assembly for this Boiler Feed Pump Motor (9000HP, 1800RPM, 13,200v, Siemens …
October 24, 2016
Before Reading – Please see the first article in this Case Study Series: “On-Site Findings.” The results of the “on-site” findings resulted in the determination to pull this Boiler Feed Pump Motor (9000HP, 1800RPM, 13,200v, Siemens Allis) out for repair. The motor was removed and was received by the HECO motor repair shop on 3-31-2015. …
October 8, 2016
On March 09, 2015, HECO was called in to help evaluate vibration and noise concerns with a coal-fired power generation plant’s Boiler Feed Pump Motor. (9000HP, 1800RPM, 13,200v, Siemens Allis). Initial information from the plant vibration team indicated rotor related issues. Review of the data provided showed a possible rotor bar pass frequency. This is …
August 11, 2016
Before reading about these different tests, please check out our last few articled on electric motor theory and rotor bar cracks: How Does an Induction Electric Motor’s Rotor Work? How do 2-pole Electric Motor Rotor Bars Crack? Besides a simple visual inspection, below is a summary of the most common methods of detecting cracked rotor …
Subscribe to our blog and get tips and updates to optimize your electric motor powertrain.