A fundamental concept behind the operation of alternating current systems is that voltage and current waveforms will be sinusoidal – a Sine Wave. This...

The windings of many medium and small sized transformers are protected by restricted earth fault (REF) systems. The illustration shows the principal of...

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...

Often us engineers get so bogged down in equations, using software, producing drawings and writing specifications that this becomes the sole focus.   ...

Laplace transforms and their inverse are a mathematical technique which allows us to solve differential equations, by primarily using algebraic methods...

Some colleagues had an issue earlier in the week on sizing conduits to be cast in concrete for some power cables . It became clear that none of us had...

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

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

Photovoltaic (PV) cells (sometimes called solar cells) convert solar energy into electrical energy.  Every year more and more PV systems are installed...

Power factor is the ratio between the real power (P in kW) and apparent power (S in kVA) drawn by an electrical load. The reactive power (Q in kVAr)...