9 Most Common Power Quality Problems
The most common types of Power Quality problems are presented below along with their description, causes and consequences: Voltage sag (or dip) Very short interruptions Long interruptions Voltage spike Voltage swell Harmonic distortion Voltage fluctuation Noise Voltage Unbalance Description: A… Read more
Oct 20, 2014 | By Edvard Csanyi
Let’s analyse phase-to-earth faults in a single-incomer power system
Power-system protection should detect faults and isolate the faulty parts of the power system while keeping the fault-free parts in operation. Protection units are chosen according to the power-system configuration (parallel operation of generators or transformers, loop or radial power system,… Read more
Oct 17, 2014 | By Edvard Csanyi
18 key terms defined in NEC system grounding requirements
The topic of system grounding is extremely important, as it affects the susceptibility of the system to voltage transients, determines the types of loads the system can accommodate, and helps to determine the system protection requirements. The system grounding arrangement… Read more
Oct 15, 2014 | By Edvard Csanyi
14 energy-efficiency improvement opportunities in pumping systems
Pump systems consist of pumps, driver, pipe installation and controls (such as ASDs or throttles) and are a part of the overall motor system. Below some of the energy efficiency opportunities for the pumping system are presented. Also, American Society… Read more
Oct 13, 2014 | By Edvard Csanyi
An example of the effectiveness of directional overcurrent relays (ANSI 67, 67N)
When fault currents can flow in more than one direction with respect to the load current it is often desirable to determine which direction the fault current is flowing and trip the appropriate devices accordingly. This is usually due to the need… Read more
Oct 10, 2014 | By Edvard Csanyi
Applications and characteristics of overcurrent potection relays (ANSI 50, 51)
Overcurrent relays are the most commonly-used protective relay type. Time-overcurrent relays are available with various timing characteristics to coordinate with other protective devices and to protect specific equipment. Instantaneous overcurrent relays have no inherent time delay and are used for fast short-circuit… Read more
Oct 08, 2014 | By Edvard Csanyi
What Is Earth And Why And How Do We Connect To It?
The thin layer of material which covers our planet – rock, clay, chalk or whatever – is what we in the world of electricity refer to as earth. So, why do we need to connect anything to it? After all,… Read more
Oct 06, 2014 | By Edvard Csanyi
Rating Definitions Applied to Medium Voltage Fuses
The definition of low voltage fuses is equally applicable to medium voltage fuses. Medium voltage level is defined by standard ANSI C84 as containing standard system voltages from 2400 through 69,000 V, and the high voltage level contains standard system voltages from… Read more
Oct 03, 2014 | By Edvard Csanyi
Energy Efficiency Aspects of Electric Motors
Three-phase squirrel-cage induction motors comprise a considerable percentage of the electrical load in the United States. Design, operation, and maintenance of these machines is well described in some of the articles already published. This article focuses on their energy efficiency aspects…. Read more
Oct 01, 2014 | By Edvard Csanyi
8 Energy-Efficiency Improvement Opportunities In Electric Motors
When considering energy-efficiency improvements to a facility’s motor systems, a systems approach incorporating pumps, compressors, and fans must be used in order to attain optimal savings and performance. In the following, considerations with respect to energy use and energy saving… Read more
Sep 29, 2014 | By Edvard Csanyi
3 Photovoltaic Installation Terms To Be Familiar With
In order to understand a photovoltaic (PV) installation and its components we must be familiar with the following terms: Standard Test Conditions (STC) PV modules PV string and Array The output of a PV module is not stable it depends… Read more
Sep 26, 2014 | By Erin Ndrio
Maintenance Management Of Electrical Equipment (Condition Monitoring Based) – 6
Read previous parts of this serie – Part 1 | Part 2 | Part 3 | Part 4 and Part 5 Proper Use of Predictive Technologies Merits and Demerits of CDM program Advantages Disadvantages CDM is more than maintenance Conclusion System components, such as circuit breakers, transformers,… Read more
Sep 24, 2014 | By Ashok Parikh
The need for electric energy is never ending
As you guess, yes, the need for electric energy is never ending. Along with the growth in demand for electric power, sustainable development, environmental issues, and power quality and reliability have become concerns. Electric utilities are becoming more and more… Read more
Sep 22, 2014 | By Edvard Csanyi
Rating Definitions Applied to Low Voltage Molded-Case Circuit Breaker (MCCB)
The molded-case circuit breaker is the “workhorse” for system protection 600V and below. A circuit breaker is a device designed to open and close by nonautomatic means and to open the circuit automatically on a predetermined overcurrent without damage to itself when… Read more
Sep 19, 2014 | By Edvard Csanyi
10 Things to Consider When Selecting a High Quality Medium Voltage Drive
Medium voltage drives have been available for over 35 years, but have only recently achieved very high reliability and simplicity within the past few years. Below are 10 considerations on how I would go about specifying and selecting a very… Read more
Sep 17, 2014 | By Craig Hartman
