A UPS is an uninterruptible power supply.  It is a device which maintains a continuous supply of electrical power, even in the event of failure of the...

Often document control is dictated by project requirements, for example a particular organisation may have an existing numbering system. Existing company...

I was reminded of Occam's Razor while reading a book. It's quite a simple principal of logic which has stood the test of time and is accepted as central...

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...

Lead acid batteries are cost effect and reliable, making them suitable for many applications.This note examines topics of interest associated with the...

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

Depending where in the world you work, you are likely following one of two standards International Electrotechnical Commission (IEC) National...

Electrical notes are a collaborative collection of electrical engineering information and educational material. Any registered user can add content. ...

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

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)...