Variable frequency drives are widely used to control the speed of ac motors.  This note looks at the mechanisms which enable drive units to control the...

A recurring theme on our forums is cable sizing. Now many installations are unique and require special consideration. However, a lot of the time things...

When sizing cables nearly, everyone uses some form of software. This ranges from homespun spreadsheets to complex network analyses software. Each has its...

Anyone specifying or using electric motors should have a basic understanding how the insulation is related to temperature. Three classes of insulation...

One of the requirements to ensuring that everything works is to have equipment selected, manufactured and verified [tested] to IEC standards. Not all equipment...

We have had the Wiki with us for a long time now, but at last I have decided to say bye bye – more details on why below.

Motor starting and its associated problems are well-known to many people who have worked on large industrial processes. However, these things are, of course...

The 27 km, Euro 6 billion  Collider lies on the border between France and Switzerland, took nearly 30 years to complete.  Some of the lofty goals for the...

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

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...