How to test/record evidence of intermittent electrical outages?


ELECTRICAL Engineering Interview Questions with Answers free download – EEE :-


1. What is electric traction?

Electric traction means using the electric power for traction system (i.e. for railways,trams, trolleys etc). Electric traction means use of the electricity for all the above machines. Now a days, magnetic traction is also used for bullet trains.and basically dc motors are used for electric traction systems.

2. How can you start-up the 40w tube lite with 230v AC/DC without using any choke/Coil?
It’s possible by means of Electronic chokes,otherwise it’s not possible to ionize the particles in tube light with normal voltage.

3. What is “pu” in electrical engineering?
Pu stands for per unit and this will be used in single line diagram of power distribution and it is like a huge electrical circuit with no of components (generators, transformers, loads) with different ratings (in MVA and KV). To...

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One of the primary challenges facing developing countries that are attempting to build a robust electric grid is “tariff under-recovery” – many customers do not pay their electric bills. A consequence is that utilities are unable to cover operating expenses, maintain their existing infrastructure, and fund new investment to accommodate growth in electricity demand. In Ghana, load shedding – often referred to as “dumsor” – has risen dramatically in recent years. It is widely believed that load shedding is a major barrier to economic growth. It is estimated that intermittent power leads to a loss of productivity and economic growth on the order of $320- $924 million per year, or 2-6% of GDP.

Industry experts have conjectured that there is a dangerous negative feedback loop that exists between tariff under-recovery and load shedding. To the best of our knowledge, no research has tested for evidence of this feedback loop or investigated methods to mitigate such negative feedback...

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The full article


This article is a basic discussion of the issue of business exposure to electric utility service outages. It surveys a range of approaches to reduce those exposures or ease their impact. These include contractual answers, such as service interruption insurance, and physical answers, such as installed back-up power supply equipment. The following information serves as an introduction; more in-depth information can be found in previous Locomotive articles which are listed at the end of this discussion.

How Electrical Distribution Works

Most electrical power used in North America is generated at large, investor-owned power plants. These are generally coal fired, oil fired, natural gas fired, nuclear or hydroelectric, but there are some alternate energy utility plants as well.

The voltage of electrical power is stepped up or down using transformers. Typically, power is stepped up near the generating plant to high...

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Specific scenario

While I don't want to concentrate on only the issue I am having, here are some details of the current issue we face and how I've tackled it so far.

The issue occurs when the user interacts with the user interface (a TabControl to be exact) at a particular phase of a process. It doesn't always occur and I believe this is because the window of time for the problem to be exhibited is small. My suspicion is that the initialization of a UserControl (we're in .NET, using C#) coincides with a state change event from another area of the application, which leads to a font being disposed. Meanwhile, another control (a Label) tries to draw its string with that font, and hence the crash.

However, actually confirming what leads to the font being disposed has proved difficult. The current fix has been to clone the font so that the drawing label still has a valid font, but this really masks the root problem which is the font being disposed in the first...

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The Circuit Detective's Diagnostic Tree

If you have reached this page without beginning at the Start of the diagnostic tree, you may do better to start there.

You have described an intermittent outage. (A recessed light fixture is designed to go off temporarily when it has overheated [from wrong light bulb or hot environment].) When a whole set of lights and/or outlets stop working for a time, this is from a poor connection, usually at an electrical box or device along the circuit, but possibly at the panel or on the power company's line to your house.

While an outage is still going on, a procedure I describe for disturbing a poor connection back into working can often help. It is at Open. If power is currently still working, however, it is more difficult to find where this weakness has occurred. But the procedure just mentioned may be of value in bothering the connection back into an outage (which will tell you exactly where the problem lies). In addition it may help...

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Electricity is a form of energy and it occurs in nature, so it was not “invented.” As to who discovered it, many misconceptions abound. Some give credit to Benjamin Franklin for discovering electricity, but his experiments only helped establish the connection between lightning and electricity, nothing more.

The truth about the discovery of electricity is a bit more complex than a man flying his kite. It actually goes back more than two thousand years.

In about 600 BC, the Ancient Greeks discovered that rubbing fur on amber (fossilized tree resin) caused an attraction between the two – and so what the Greeks discovered was actually static electricity. Additionally, researchers and archeologists in the 1930’s discovered pots with sheets of copper inside that they believe may have been ancient batteries meant to produce light at ancient Roman sites. Similar devices were found in archeological digs near Baghdad meaning ancient Persians may have also used an early form...

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NBER Working Paper No. 19510
Issued in October 2013
NBER Program(s):Environment and Energy Economics

Digital tracking and the proliferation of automated payments have made intermittent billing more commonplace, and the frequency at which consumers receive price, quantity, or total expenditure signals may distort their choices. This category of goods has expanded from household utilities, toll road access and software downloads to standard consumption goods paid by credit card or other "bill-me-later"-type systems. Yet we know surprisingly little about how these payment patterns affect decisions. This paper exploits hourly household electricity consumption data collected by "smart" electricity meters to examine dynamic consumer behavior under intermittent expenditure signals. Households reduce consumption by 0.6% to 1% following receipt of an electricity bill, but the response varies considerably by household type and season. Our results also suggest that...

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Electrical and Electronic Intermittent Troubleshooting Strategy Electrical and Electronic Intermittent Troubleshooting Strategy

Many, if not most, electrical or electronic system faults on modern vehicles and equipment are intermittent in nature. This means that normal test procedures designed for constant (hard) faults will be ineffective. Test measurements made while the problem is not occurring will generally result in normal readings. There are several things one can do to chase these illusive faults down. The following information is some of the strategies that have been found to be effective in real world troubleshooting.

The first thing you need to do for any intermittent fault troubleshooting is to verify the operators complaint. In some cases the operators complaint may be normal operation. It is important that you communicate with the person who actually experienced the fault to get a clear understanding of exactly what his/her concern is. Once you have...

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