Electric Motors

By Steven McFadyen on 3/28/2012 1:12 PM

Collection of links to various places with useful motor information. I’ll try and return to the page every now and again to update it with any motor notes added to the site. read more..


How a Digital Substation Works

By Steven McFadyen on 3/2/2014 12:06 PM

Traditionally substations have used circuit breakers, current transformers (CT), voltage transformers (VT) and protection relays all wired together using copper cables.  With advances in digital... read more..


The ac resistance of conductors

By Steven McFadyen on 1/11/2012 4:03 PM

In a previous article I looked at the dc resistance of conductors and in this article we turn our attention to ac resistance. If you have not read the previous article, now may be a good time to do so. ... read more..


Restricted Earth Fault Protection

By Steven McFadyen on 3/25/2012 12:49 PM

The windings of many medium and small sized transformers are protected by restricted earth fault (REF) systems. The illustration shows the principal of REF protection. read more..


Cable Insulation Properties

By Steven McFadyen on 5/15/2012 6:13 AM

Cable insulation is used to provide electrical separation between conductors of  a cable.  During the historical development of cables, numerous types of insulation have been employed. ... read more..


Photovoltaic (PV) Panel - Performance Modelling

By Steven McFadyen on 1/8/2015 3:55 AM

In an earlier note on the site [Photovoltaic (PV) - Electrical Calculations], the theory of solar (PV) ... read more..


Load Flow Study – how they work

By Steven McFadyen on 12/8/2014 10:25 AM

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 the electrical network. Carrying out a load flow s... read more..


Thermoplastic and Thermosetting Insulation

By Steven McFadyen on 7/6/2011 3:12 AM

While there are a vast array of cable insulation materials, these are often divided into two general types; Thermoplastic or Thermosetting. For example the current capacity determination of a cable in a... read more..


Arc Flash Calculations

By Steven McFadyen on 3/22/2012 6:14 AM

Working in the vicinity of electrical equipment poses an hazard. In addition to electric shock hazard, fault currents passing through air causes Arc Flash. To protect people a risk analysis on the ar... read more..


Motor Starting - Introduction

By Steven McFadyen on 8/11/2011 1:28 AM

Motor starting and its associated problems are well-known to many people who have worked on large industrial processes. However, these things are, of course, less familiar to others.  This post ... read more..


Tips for a better Low Voltage Protection Discrimination Study

By Steven McFadyen on 11/3/2014 11:48 AM

Carrying out a protection system discrimination study is critical to ensure the correct functioning of  the electrical system in the event of faults.  The IEC defines discrimination as:

... read more..


What is an Open Delta Transformer

By Steven McFadyen on 10/13/2014 11:54 AM

In three phase systems, the use of transformers with three windings (or legs) per side is common.  These three windings are often connected in delta or star, resulting in common transformer conf... read more..




Famous Scientists

Here’s list of some famous scientists. Deliberately short, with the aim to provide a quick memory jog or overview. If your looking for more detailed information...

Three Phase Power Simplified

A single phase system is perhaps the most common type of system most people are familiar with. This is what people have in their homes and what appliances...

How Electrical Circuits Work

If you have no idea how electrical circuits work, or what people mean then they talk about volts and amps, hopefully I can shed a bit light.  I’m intending...

Are We Losing Professional Integrity

I have been thinking recently that there appears to be less professional integrity around than when I first started my career in electrical engineering...

Robotics - Home Innovations

We have a sister note to this (Robots - Interesting Video), in which I have posted some videos of interesting robots developed by commercial corporations...

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...

Questions - Reputation and Privilege

Our question and answer system while letting you do exactly what it says, is much more.  It is a dynamic user driven system, where our users not only ask...

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...

Electromechanical Relays

Electromechanical relays have been the traditional backbone of electrical protection systems.  While over recent years these have been replaced by microprocessor...

What does N+1 mean?

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...

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