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..




IEC 61439 - The Switchgear Standard

The new standard IEC 61439 replaces the old 60439. Compared to the old standard, the new 61439 is a more clearly defined and takes into account the assembly...

What is a rectifier transformer?

I've recently come across this question a couple times browsing the internet. Decided to give a quick answer here. A rectifier transformer is a transformer...

Calculating Cable Fault Ratings

When selecting a cable, the performance of the cable under fault conditions is an important consideration. It is important that calculations be carried...

Copyright Infringement

myElectrical does not support or promote the use of copyrighted material without the copyright owner's consent. If you believe that material for which...

Arc Flash Calculations

Working in the vicinity of electrical equipment poses an hazard. In addition to electric shock hazard, fault currents passing through air causes Arc Flash...

How to Check a Circuit is Dead

If you want to check a circuit is dead (not live), you should always use the three point method. First check a known live circuit, then check the dead...

DC Component of Asymmetrical Faults

The image (reproduced from IEC 60909) shows a typical fault in an ac system.  From the illustration it can seen that there is an initial dc component ...

Cable Sizing Software

When sizing cables nearly, everyone uses some form of software. This ranges from homespun spreadsheets to complex network analyses software. Each has its...

Load Flow Study – how they work

A load flow study is the analysis of an electrical network carried out by an electrical engineer. The purpose is to understand how power flows around...

Cold Fusion (or not?)

Recently I have seen a few interesting articles on viable cold fusion; the combining of atoms at room like temperatures to create boundless energy. Now...

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