The correct sizing of current transformers is required to ensure satisfactory operation of measuring instruments and protection relays. Several methods...

Following on from my post on railway electrification voltages, I thought an introduction to traction substations would be a good idea. Traction substations...

A frequent problem in fault calculations is the obtaining of equipment parameters.  While it is always preferable to use the actual parameters of the equipment...

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

I was reminded of Occam's Razor while reading a book. It's quite a simple principal of logic which has stood the test of time and is accepted as central...

IEC 61439 'Low-voltage switchgear and controlgear assemblies', specifies standard arrangements of switchboard (call forms of internal separation). The...

Our cable sizing tool is one of the more popular tools on the site.  The tool enables cables to be sized in compliance with BS 7671 (the IEE Wiring Regulations...

Most installations involve some form of lightning protection system which is connected to an earth electrode.  The function of the earth electrode is to...

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...

The other day I was reading 'Night of the New Magicians' by Mary Pope Osborn with my son.  The story is about a young boy and girl who travel back in time...