by Howard Penrose, Ph.D., CMRP | Jul 25, 2020 | Electrical Reliability, Motors & Drives
The standards working group behind the present edition of IEEE Std 43 made substantial changes in the overall standard, including modifications to temperature normalization to 40 C. This was done to accommodate the many changes and observations in insulation chemistry...
by Howard Penrose, Ph.D., CMRP | Jul 10, 2020 | Electrical Reliability, Motors & Drives
As discussed in the July 3, 2020, installment of this ongoing series the insulation-to-ground tester, or Meg-Ohm meter, was also one of the earliest instruments used by technicians to evaluate and troubleshoot insulation systems. That includes...
by Howard Penrose, Ph.D., CMRP | Jul 3, 2020 | Electrical Reliability, Motors & Drives
This article is part of a continuing series that began with discussions of IEEE and EPRI large-electric-motor studies and what those studies considered “excellent maintenance.” At this point, the series has moved beyond the emphasis on large motors and,...
by Howard Penrose, Ph.D., CMRP | Jun 19, 2020 | Electrical Reliability, Motors & Drives
When reviewing the IEEE and EPRI large electric motor studies on which this ongoing article series has focused, and looking at what those studies considered as “excellent maintenance,” a number of concerns surfaced. Among them was the fact that many...
by Howard Penrose, Ph.D., CMRP | Jun 13, 2020 | Electrical Reliability, Motors & Drives
From previous articles in this series on large-electric-motor studies conducted by EPRI and IEEE, we’ve noted the fact that there were potential issues with the findings, including in the area of industry best practices related to component replacement through repair....
by Howard Penrose, Ph.D., CMRP | May 29, 2020 | Electrical Reliability, Motors & Drives
In this installment of an ongoing series, we’ll discuss what was learned during a five-year period at a site containing 46 4160V through 13,800Volt electric motors, and compare these findings to data from large-motor studies conducted by EPRI (Electric Power...
by Howard Penrose, Ph.D., CMRP | May 2, 2020 | Electrical Reliability, Motors & Drives
This article is the latest installment of a multi-part discussion on research conducted by EPRI (Electric Power Research Institute) and IEEE (Institute of Electrical and Electronics Engineers). As we dig deeper into those studies, some intriguing patterns begin to...
by Howard Penrose, Ph.D., CMRP | Apr 18, 2020 | Electrical Reliability, Motors & Drives
This article continues a multi-part discussion on research conducted by EPRI (Electric Power Research Institute) and IEEE (Institute of Electrical and Electronics Engineers). As noted in the two previous installments of this series (see links at the end of this...
by Howard Penrose, Ph.D., CMRP | Apr 12, 2020 | Electrical Reliability, Motors & Drives
What did the 1983 EPRI study and subsequent IEEE studies of large electric motors really say? With the EPRI study primarily identified as one on motor failures, the focus of this article is related to how the reported findings iof that research compare to those of the...
by Howard Penrose, Ph.D., CMRP | Mar 28, 2020 | Electrical Reliability, Motors & Drives
The graph in Fig. 1 below is often quoted as showing the average failure rates in a population of electric motors throughout industry, and cited as the results of a 1983 Electric Power Research Institute (EPRI) study. This General Electric study of large power-plant...
