Variable Frequency Drives (VFDs) are increasingly common, especially with the push for energy efficiency (in residential applications) and better motor control (in industrial applications). Unfortunately, the gains made with VFDs…
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Understanding Recording Modes
Recorders connected in ProVision have two primary modes: Standby mode and Ready mode. Each of these modes has a distinct purpose, and some recorder operations in ProVision require the recorder…
Per-Unit Graphing with Canvass
Canvass is a web-based power quality portal designed and developed by PMI to allow users to perform power quality analysis from anywhere they have an internet connection and a web…
CBEMA and ITIC Curves
The CBEMA and ITIC curves are both used to visibly represent voltage events. The terms and associated curves are used somewhat interchangeably even though there are subtle differences between the…
Understanding IEEE Flicker, IFL, Pst, Plt
This white paper covers and explains three of IEEE's most common Flicker definitions: IFL, Pst and Plt. The GE Flicker Curve and how other measurements standards compare to the GE…
Measuring Frequency with PMI Recorders
Line frequency is the most tightly controlled parameter in the electrical distribution system. Since almost all generation in a region is connected essentially in parallel, the frequency is inherently synchronized…
Monitoring a 2½ Element Wye
A 2½ Element WYE Configuration uses 3 current phases and 2 voltage phases to calculate what is on the third voltage phase in order to measure the total power on…
Arithmetic vs. Vector Power
The basic formulas for RMS voltage, current, power, etc. in a simple single-phase circuit are well-defined and universal. For polyphase systems, the situation is more complex: in the 3-phase delta…
Top Ten Field Tips for PMI Recorders and Provision
A few simple steps can streamline data file analysis and help you make the most of each recording. This white paper covers 10 tips and techniques that come in useful…
Computing Event Duration with Histogram Data
The cycle histogram is an important, but underused record type available with all PMI recorders. The histogram doesn't require any configuration, spans the entire recording session (no possibility of memory…
THD-F vs THD-R
There are two typical definitions used when dealing with Total Harmonic Distortion. The two types of Total Harmonic Distortion are THD-F and THD-R. They both are figures of merit used…
Histograms in ProVision
ProVision software includes the ability to analyze power quality data with several different graph types. This paper will focus on ProVision's histogram graphs. ProVision includes ten different types of histogram…