Operational Amplifier
The fundamental component of any analogue computer is the operational amplifier, or op amp. An operational amplifier (often called an op-amp,) is a high...
Switchboard - Forms of Internal Separation
IEC 61439 'Low-voltage switchgear and controlgear assemblies', specifies standard arrangements of switchboard (call forms of internal separation). The...
myElectrical - Cable Sizing Tool Upgrade
Our IEE cable sizing was wrote a few years ago and had become rough around the edges. I thought it was time to give the tool a service. Unfortunately when...
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...
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...
Aluminium Windings - Dry Type Transformers
The other day I was talking to a colleague who is a building services consultant. Despite regularly specifying dry-type/cast resin transformers he was...
3 Phase Loads
Three phase systems are derived from three separate windings, either connected in delta or star (wye). Each winding can be treated separately, leading...
9 power supply issues solved by using a UPS
Installation of a UPS can help in reducing problems due to issues with the power supply. A lot of people relate this to nine key issues. Depending on...
How a Digital Substation Works
Traditionally substations have used circuit breakers, current transformers (CT), voltage transformers (VT) and protection relays all wired together using...
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...