Cables for MV Power Distribution - Earthed versus Unearthed Systems
Power cables can basically be classified into earthed and unearthed cables, where earthed and unearthed refer to the application for which the cable is...
Lead us, Warleader
Delum, who had watched all in silence, his face empty of expression, now spoke in turn. ' "Lead us, Warleader, into glory."'
Reading is something I do...
What is an Open Delta Transformer
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...
Switchboard - Forms of Internal Separation
IEC 61439 'Low-voltage switchgear and controlgear assemblies', specifies standard arrangements of switchboard (call forms of internal separation). The...
Photovoltaic (PV) - Utility Power Grid Interface
Photovoltaic (PV) systems are typically more efficient when connected in parallel with a main power gird. During periods when the PV system generates energy...
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...
DC Component of Asymmetrical Faults
The image (reproduced from IEC 60909) shows a typical fault in an ac system. From the illustration it can seen that there is an initial dc component ...
Voltage Drop in Installations - Concepts
Problems on achieving maximum voltage drop within an installation come up often. Depending where you live, local regulations will have different limits...
Lightning Protection and Earth Electrode Resistance
Most installations involve some form of lightning protection system which is connected to an earth electrode. The function of the earth electrode is to...
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...