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...
Gas Insulated or Air Insulated Switchgear
Various arguments exist around SF6 Gas Insulated (GIS) and Air Insulated (AIS) medium voltage switchgear. Recently we had to change a GIS design to AI...
Voltage Levels to IEC 60038
The standard aims to consolidate AC and traction voltages within the industry and defines the following bands:
band 1 - A.C. systems 100 V to 1...
Inductance
When current flows within a wire, a magnetic field is created. The potion of this magnetic field perpendicular to the wire is called the magnetic flux...
Back to Basics - Ohm’s Law
Electrical engineering has a multitude of laws and theorems. It is fair to say the Ohm's Law is one of the more widely known; it not the most known. Developed...
IEC 60287 Current Capacity of Cables - Rated Current
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...
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...
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...
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...
Nikola Tesla
Nikola Tesla was born exactly at midnight on July 10, 1856 in the tiny village of Smiljan, Lika in Croatia. In his late teens, Tesla left the village to...