"cynic" wrote in message
...
On May 9, 1:11 pm, "
wrote:
On May 8, 9:13 pm, Dave W wrote:

I've just watched "Richard Hammond's Engineering Connections" on BBC2
about a new skyscraper in Dubai. Some expert told him that capacitors
and inductors were installed to smooth out the chopped up current from
the lighting dimmers, to stop the wiring overheating. We were treated
to a ridiculous demonstration in which hot wires ignited cotton wool
soaked in inflammable liquid, producing a spectacular destruction of a
wooden shed in a field.

My whole working life has been spent in electronics design, but I have
never heard of such a heating effect, and I still cannot understand
what it was all about. Can anybody provide a convincing technical
explanation?

Dave W

It's called Power Factor Correction, dimmers and many other
appliances, computers are bad for this too, draw a current that is out
of phase with the voltage, resulting in excessive 'wattless current'
flowing in the wiring, the supply mains, and the transformers, if
capacitors are not fitted near the load to absorb the 'reactive
power'.

The whole shebang was an exercise in stupidity. There really ought to
be a law against lettiing the unknowing spout their drivel in the
public media.

Where did they get their "expert" as if he had any sort of
professional status his learned society ought to take him to task.

"Ex" is a has-been, and "spert" is a drip under pressure!