From the monthly archives: October 2011

We are pleased to present below all posts archived in 'October 2011'. If you still can't find what you are looking for, try using the search box.

Tip – Latitude and Longitude on Large Scale Plans

By Steven McFadyen on 10/29/2011 8:26 AM

If you are working on a large plan, get the real coordinates [latitude, longitude] for two or more points and add them to the drawing. That way you can always work out the scale and dimensions.

... read more..


Back to Basics - Ohm’s Law

By Steven McFadyen on 10/21/2011 2:02 PM

Electrical engineering has a multitude of laws and theorems. It is fair to say the Ohm's Law is one of the more widely known; it not the most known. Developed in 1827 by Georg Ohm the law defines the re... read more..


What does N+1 mean?

By Steven McFadyen on 10/19/2011 5:40 AM

The term 'N+1' relates to redundancy and simply means that if you required 'N' items of equipment for something to work, you would have one additional spare item. If any one item of equipment breaks dow... read more..


Always Use PPE

By Steven McFadyen on 10/12/2011 7:25 AM

A lot of our members work in countries where PPE (personal protective equipment) is regulated or they work for companies/organizations which take employee safety seriously. Unfortunately, there are plac... read more..


Welcome back Bottle

By Steven McFadyen on 10/9/2011 2:23 PM

‘Kept looking at a card, y’see? Kept looking at it. Welcome back Bottle. Gods below welcome home.

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Differential protection, the good old days

By Steven McFadyen on 10/3/2011 1:52 PM

This morning I was explaining how differential protection works to a junior engineer. To give him something to read I opened up the NPAG (Network Protection and Automation Guide, by Areva) and turned to... read more..




Low Voltage Circuit Breakers

Circuit breakers are switching devices whose primary function is to isolate parts of an electrical distribution system in the even of abnormal conditions...

Low Voltage Fault Tables

The following tables provide quick order of magnitude fault levels for a a range of typical low voltage situations.

Smarter Electrical Distribution

The other day I came across an article in Technology Review on the development of a smart transformer. A professor at North Carolina State University is...

Back to Basics - Ohm’s Law

Electrical engineering has a multitude of laws and theorems. It is fair to say the Ohm's Law is one of the more widely known; it not the most known. Developed...

Voltage Levels – Confused?

I was having a conversation the other day about voltage levels.  While everyone was in agreement that low voltage was 1000 V and less, there was more confusion...

Large Hadron Collider

The 27 km, Euro 6 billion  Collider lies on the border between France and Switzerland, took nearly 30 years to complete.  Some of the lofty goals for the...

Batteries

A battery consists of one or more cells, each of which use stored chemical energy to produce electrical energy, There are many types of cells and these...

Fault Calculation - Per Unit System

Per unit fault calculations is a method whereby system impedances and quantities are normalised across different voltage levels to a common base.  By removing...

Battery Sizing

This article gives an introduction to IEEE 485 method for the selection and calculation of battery capacity.

Star-Delta Motor Starting - Performance

Many questions sent in to the site are in connection with motor starting and in particular star-delta.  For all but the simplest application, there is...

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