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...

Our cable sizing tool is one of the more popular tools on the site.  The tool enables cables to be sized in compliance with BS 7671 (the IEE Wiring Regulations...

IEC 60228 is the International Electrotechnical Commission's international standard on conductors of insulated cables. Among other things, it defines a...

Many questions sent in to the site are in connection with motor starting and in particular star-delta.  For all but the simplest application, there is...

Power cables can basically be classified into earthed and unearthed cables, where earthed and unearthed refer to the application for which the cable is...

Traditionally substations have used circuit breakers, current transformers (CT), voltage transformers (VT) and protection relays all wired together using...

The following tables provide quick order of magnitude fault levels for a a range of typical low voltage situations.

If you want to check a circuit is dead (not live), you should always use the three point method. First check a known live circuit, then check the dead...

Dielectrics (insulating materials for example) when subjected to a varying electric field, will have some energy loss.   The varying electric field causes...

For unbalance conditions the calculation of fault currents is more complex. One method of dealing with this is symmetrical components. Using symmetrical...