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...

Our question and answer system while letting you do exactly what it says, is much more.  It is a dynamic user driven system, where our users not only ask...

I think this post is going to be helpful to several of our readers. While the IEC low voltage circuit breaker Standard [IEC 60947-2, Low voltage switchgear...

Photovoltaic (PV) systems are typically more efficient when connected in parallel with a main power gird. During periods when the PV system generates energy...

How often installations are inspected is up to the owner of the installation, provided such durations do not exceed any regulatory maximums in force. ...

Coils of wire on the rotor carry a d.c. current which generates a magnetic field. A stator magnetic field is created using either permanent magnets or...

When thinking about watts (W) or kilowatt (kW = 1000 W) it can be useful too keep in mind the fundamental ideas behind the unit. Watt is not a pure electrical...

Everything physical in electrical engineering from insulations to conductors revolves around materials. Here we are listing common materials along with...

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 60947 is the circuit breaker standard and covers the marking of breakers in detail. Any manufacturer following this standard should comply with the...