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.

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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..




Cable Trumps

Bored at work and would rather be playing trump card game with you son. The next best thing (or not) maybe the online cable trump card game from AEI Cables...

Autonomous Vehicle Challenge

Two driverless and solar power vans have departed from Italy on their way to China via the silk road. During the 13,000 kM trip the vans will drive themselves...

Battery Cars A to Z

Battery powered cars are a hot topic and widely debated. The pros, cons, issues and time frames can be talked about endlessly. An article by the Telegraph...

How to measure power supply quality

If your are ever called out to troubleshoot something on your electrical system, one of the first things consider is the supply voltage. You want to ensure...

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...

Introduction to Current Transformers

Current transformers (CTs) are used to convert high level currents to a smaller more reasonable level for use as inputs to protection relays and metering...

Power Factor

Power factor is the ratio between the real power (P in kW) and apparent power (S in kVA) drawn by an electrical load. The reactive power (Q in kVAr)...

Railway Electrification Voltages

This post is quick introduction and overview to different railway electrification voltages used in answer to a question sent in via email. While there...

Frame Leakage Protection

While not as popular as it once was, frame leakage protection does still have some use in some circumstances.  In essence frame leakage is an earth fault...

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...

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