[clug-talk] Slightly OT Power usage

Nick W nickw77 at shaw.ca
Sat Nov 20 09:42:22 PST 2004


On November 19, 2004 07:45 pm, Dave Watkins wrote:
<snip>
> Concerning the use of surge protectors in most cases you get what you pay
> for. It's as simple as that. Just for fun one day I hooked a battery
> charger to a surge protector and placed a rheostat in line between the
> surge protector and a 220 V power supply. I was surprised to see the range
> that they would accept without tripping. That increase or decrease in
> voltage, known as sags or surges, can cause as much damage to today's
> modern systems and the data on them. Today's systems are more delicate due
> to the smaller voltages required to operate. During a discussion with the
> City of Calgary's Electrical Dept I was told that the voltage provided by
> the City can vary by as much as 15% from 110V. I was also surprised to find
> out that this variance is "normal" according to the City and within the
> contract we all have accepted by using their power. Most surge protectors
> do not have the circuitry within to react fast enough to these surges or
> sags. Another consideration is the speed which a surge protector will kick
> in, sometimes called the clamping voltage. With many of the cheaper units
> the damage has been done before the protector realizes there has been a
> spike.


On this note, I remember my teacher from back in the day, who has a masters in 
electronics saying when shopping for a surge protector, don't buy one that 
simply says '110 volt' on it. That value means little when dealing with AC, 
as our power actually goes from 170V+ to 170V- at 60Hz. 110V is the RMS 
value. Instead buy one that protects '170V peak to peak' and you will get 
better protection.

Though with the prices quoted, a UPS sounds like a much better option anyways.
<snip>

Nick



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