From the monthly archives: May 2009

We are pleased to present below all posts archived in 'May 2009'. If you still can't find what you are looking for, try using the search box.

UPS Sizing - Rules of Thumb

By Steven McFadyen on 4/30/2009 12:56 AM

It wasn't so long ago I was telling someone that I don't use rules of thumb as most things are easily calculated anyhow.   As it turns out I last week I ended up using what can only be describ... read more..




Alternating Current Circuits

Alternating current (a.c.) is the backbone of modern electrical power distribution. In this article I’ll be pulling some of the more important concepts...

1,000 kV UHV First for China

At the beginning of the year China put the world's first 1,000 kV UHV transmission system into operation. Transmitting power at over a million volts is...

Introduction to Current Transformers

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...

Large Hadron Collider

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...

Power Factor

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)...

Fire Resistant and Fire Retardant Cables

Fire resistant and fire retardant cable sheaths are design to resist combustion and limit the propagation of flames. Low smokes cables have a sheath designed...

What are you reading!

Reading is a bit of a hobby of mine and I"ve done a few off-topic posts in the past on this. Rather than continue doing the occasional post I thought ...

Photovoltaic (PV) Panel - Performance Modelling

In an earlier note on the site [Photovoltaic (PV) - Electrical Calculations], the theory of solar (PV) cell calculations was introduced.  In particular...

Low Voltage Fault Tables

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

Why a Sine Wave?

I received this question by email a few weeks. First thoughts was that it is a product of the mathematics of rotating a straight conductor in a magnetic...

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