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…
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…
What is the impact of an electrical reliability program? Or even the application of a precision maintenance program Overall, the transition to a planned maintenance program from a reactive program has been identified by the US Department of Energy (US DOE) Industrial Assessment Centers (IAC) as having at least 14% improvement of all energy consumption…
A reading of the new book on Electrical and Current Signature Analysis by MotorDoc LLC which is planned for release in the second half of October, 2022.
Media bias is not only found related to politics and public policy, but also how we perceive the reliability and maintenance community. From advertising dollars and marketing being presented as technical articles and information to the idea that ‘digital transformation’ solves everything, or that infrared is a complete electrical reliability program. As noted in my…
It is established that neutral and ground harmonic content will load transformers and systems. Prior work has been limited as to the direct relationship of this additional loading on power consumption for a facility. Over the past 24 months applied research has been performed on the measured impact of neutral and ground harmonics and energy…
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…
Abstract— Electrical Signature Analysis is the application and analysis of Voltage and Current data collected on electrical machinery systems. The measurements are converted to amplitude modulated Fast Fourier Transforms that can be evaluated for power, machine and powertrain conditions. Electrical and mechanical conditions are determined through their effects on the airgap magnetic field. One of…
An evaluation of several insulation types at various degrees of vacuum using repetitive discharge inception and extinction voltage offline testing will be presented. Insulation systems were evaluated in atmosphere and compared to values to 1mmHg using a commercial partial discharge surge tester. The insulation systems evaluated include unvarnished windings, dip and bake epoxy, epoxy trickle…
