Electric Motor Repair for Low Voltage Induction Motors in PWM Inverter Duty Environments
I still find it amazing that people are coming out with the same thing that we came out with in the 1990s when PWM drives made their dramatic push into industry – and presenting it all as somehow ‘new.’ In any case, here is another IEEE Electrical Insulation Conference paper published in 1997 from research…
The Mechanical Effects from Thermal Stripping Induction Motor Stators
Back in 1997 Leo Dreisilker, the president of Dreisilker Electric Motors, and I, while I was at a small engineering firm doing what we now call digital twin and machine learning, performed a study on the mechanical impacts of different stator materials when exposed to burnoff ovens. This was published in the 1997 at the…
Anatomy of an Energy Efficient Electric Motor Rewind
An IEEE article published in the IEEE Electrical Insulation Magazine January/February 1997 during the period where we were developing US Department of Energy motor management programs (Motor Challenge). The information is as true today as it was in 1997.
Evaluation of the Impact of Harmonics on Electric Machine Reliability
Power, magnetic and ground harmonics have a negative impact on the reliability of your electric motors both electrically and mechanically. We often focus just on the power harmonics when reviewing information on power quality, but rarely view the self-generated electric machine harmonics and the harmonic content present in grounds and neutrals. Over the past several…
Stator Core Loss and Hot Spot Testing: An Overview
What is the importance and differences between core loss testing and hot spot testing in electric machines through the repair process? How are they performed and what results do they provide? In this short article we will discuss the basics of core and hot spot testing and their impact on electric machine reliability. This white…
Reliability Engineering, Data Science, Machine Learning and Bias
When dealing with statistical analysis and probabilities its often the missing information that can be an issue. This can result in bias when working in areas such as reliability, data science and machine learning that result in incorrect solutions. We’ve seen that in such things as the percentage of type of motor failures, faulty IoT…
Concepts in Reliability Keeping it Simple and Random Thoughts
As I just mentioned to a friend – I seem to be waxing philosophical this past weekend as I complete reading “Wizard: The Life and Times of Nikola Tesla, Biography of a Genius,” by Marc J Seifer. I would not have tripped over this and several other excellent texts had I not started returning to…
Troubleshooting a VFD Fault Instantaneous Trip Including Bypass
A new inline ventilation motor operating on a VFD with bypass tripped on startup with the VFD and instantaneously tripped when tested across the line. Smoke was noted in the drive cabinet and MotorDoc was contacted to evaluate the electric motor and work with the VFD installer following recommendations by repair shops to remove the…