Voltage Levels – Confused?
I was having a conversation the other day about voltage levels. While everyone was in agreement that low voltage was 1000 V and less, there was more confusion...
Tech Topics/Application Notes - Siemens
There are a lot of interesting two page type notes on various medium voltage topics – switchgear, circuit breakers, bus systems etc. It is on the Siemens...
Arc Flash Calculations
Working in the vicinity of electrical equipment poses an hazard. In addition to electric shock hazard, fault currents passing through air causes Arc Flash...
How to Size Current Transformers
The correct sizing of current transformers is required to ensure satisfactory operation of measuring instruments and protection relays. Several methods...
Batteries
A battery consists of one or more cells, each of which use stored chemical energy to produce electrical energy, There are many types of cells and these...
Restricted Earth Fault Protection
The windings of many medium and small sized transformers are protected by restricted earth fault (REF) systems. The illustration shows the principal of...
Introduction to Current Transformers
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...
Post Editing Tips
If you at all familiar with programs like office and outlook, then adding and editing posts is pretty straightforward and intuitive. However, there are...
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...
110 or 230 Volts
I've been considering a blog on the 110 or 230 Volt issue for a while. While browsing the Internet I came across a great summary by Borat over at engineering...