by Howard Penrose, Ph.D., CMRP | Jan 10, 2022 | Asset Management, Electrical Reliability
In most of my articles, the terms Electrical Signature Analysis (ESA) and Motor Current Signature Analysis (MCSA) have been interchangeable. There are, however, differences in how the in-depth analysis of both voltage and current views the system versus just the...
by Howard Penrose, Ph.D., CMRP | Jan 2, 2022 | Asset Management, Electrical Reliability
As noted in Part IV of this series (see link below), determining the potential life of a machine can be relatively complex and, thus, call for some detailed experimental studies. In this series installment, we will review the potential life of the insulation on a...
by Howard Penrose, Ph.D., CMRP | Dec 4, 2021 | Electrical Reliability, RAM Tools & Methods
A bearing fails in a variable frequency drive (VFD) application. The response is to apply a shaft brush and insulated bearing. A critical electric motor shorts to ground. The response is to rewind or replace the motor and continue business as usual. When equipment...
by Howard Penrose, Ph.D., CMRP | Nov 27, 2021 | Electrical Reliability, RAM Tools & Methods
In Part III of this article series (Nov. 20, 2021, see link below), we discussed common and linear-type failure modes from mechanical systems as represented in the P-F curve. Mechanical equipment fails in terms of a “natural log” hazard curve,...
by Howard Penrose, Ph.D., CMRP | Nov 20, 2021 | Electrical Reliability, RAM Tools & Methods
If you follow topics on reliability, you may have the impression that all equipment is born, lives, and dies in the same pattern as Europeans in the 17th century. That would be with a high rate of death at birth and during their early years, average across the middle...
by Howard Penrose, Ph.D., CMRP | Nov 15, 2021 | Electrical Reliability, RAM Tools & Methods
One of the most powerful and straightforward measurements of equipment reliability is Mean Time Between Failure (MTBF), which lets the reliability engineer roughly estimate conditions surrounding a system. Some will criticize the use of MTBF as a reliability tool...
by Howard Penrose, Ph.D., CMRP | Nov 6, 2021 | Electrical Reliability, RAM Tools & Methods
The term predictive maintenance (PdM) has different meanings depending on your background and industry. Within the plant-management world, it means that if your maintenance personnel tell you that something will survive 100 hours, it will operate 100 hours, then fail...
by Howard Penrose, Ph.D., CMRP | Oct 23, 2021 | Asset Management, Electrical Reliability
As explained in Part II of this series (see links to all parts below), Electrical Signature Analysis (ESA) is used in a manner similar to vibration analysis for defects in transformers, while the electrical data provides information on other conditions surrounding the...
by Howard Penrose, Ph.D., CMRP | Oct 17, 2021 | Electrical Reliability, Motors & Drives
This week, we are taking a slight detour from our ongoing multi-part discussion on Electrical Signature Analysis (ESA) and transformers. This is because the U.S. Department of Energy (USDOE) has just released the second report (Volume 2) of its study of electric motor...
by Howard Penrose, Ph.D., CMRP | Oct 10, 2021 | Asset Management, Electrical Reliability
Popular topics around the renewable-energy community include interaction of inverter-connected power sources to the grid and the impact on components such as transformers (in particular, step-up transformers). One of the concerns with wind and solar-based step-up...
