From the monthly archives: February 2013

We are pleased to present below all posts archived in 'February 2013'. If you still can't find what you are looking for, try using the search box.

Multimeter

By Steven McFadyen on 2/28/2013 1:04 PM

Multimeters are undoubtedly the most common item of electrical test equipment in use.  Often it is the first piece of equipment people will turn to when trying to visualize and obtain data on an... read more..


IEC 60287 Current Capacity of Cables - Rated Current

By Steven McFadyen on 2/18/2013 5:58 AM

In the previous note we looked at the approach taken by the standard to the sizing of cables and illustrated this with an example.  We then looked at one method of applying the standard and iden... read more..


Introduction to Current Transformers

By Steven McFadyen on 2/8/2013 11:17 AM

Current transformers (CTs) are used to convert high level currents to a sma... read more..


HTML Symbol Entities

By Steven McFadyen on 2/6/2013 11:45 AM

HTML supports a variety of entity symbols which can be entered using either numbers or an entity name.  The number or name is preceded by the ‘&’ sign and ends in a semi-colon (;).  To ... read more..




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...

Power Transformers - An Introduction

One of the fundamental requirements of an alternating current distribution systems it to have the ability to change the magnitude of voltages.  It is more...

How a Digital Substation Works

Traditionally substations have used circuit breakers, current transformers (CT), voltage transformers (VT) and protection relays all wired together using...

Mobile Phones (Brick to Implant)

The mobile phone was born in 1973. They were the size of a brick and weighed a couple of kg, making them difficult to fit into your pocket. At a few thousand...

Periodic Electrical Installation Inspection – How Often?

How often installations are inspected is up to the owner of the installation, provided such durations do not exceed any regulatory maximums in force. ...

Differential protection, the good old days

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...

A mechanical engineering paper, some history and memories

I was digging in my bookshelf and came across the 80th Anniversary Association of Mine Resident Engineers, Papers and Discussions Commemorative Edition...

Alternating Current Circuits

Alternating current (a.c.) is the backbone of modern electrical power distribution. In this article I’ll be pulling some of the more important concepts...

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...

How to refer fault levels across a transformer

Over the past year or so I've been involved in on going discussions related to referring fault levels from the secondary of a transformer to the primary...

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