Re: damaging circuits with ????


<westom1@xxxxxxxxx> wrote in message
news:b4e85fdb-c1d1-4d19-b4cd-d7a028016a28@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
You have described what is often called an open neutral. IOW,
while he was in the electric box, he also tightened screws holding
wires. Problem solved. Voltage changes were not solved by a 'power
conditioner' - which is not what he installed.

You have told yourself (assumed) that power supplies previously were
more robust - when reality is the reverse. Today's computer power
supplies must be so robust that even dirtiest output from computer
grade UPSes do not cause damage. So robust that even startup (a more
challenging operation) occurs without problems. Computer power
supplies today must be so robust that voltage variation during normal
operation, or during startup which is more difficult; neither is
adversely affected by voltage variation.

Now, before responding, review ATX power supply specs. Power
supplies must even withstand a thousand volts without harm. Before
jumping to conclusions, read industry standards or specifications to
appreciate what that number says.

AC mains voltage must drop so low that an incandescent bulb is at
40% intensity - and all computers must both start and work just fine.
Industry standards that have existed for decades. Numbers that so
many never bother to learn when 'assuming' computers are easily
damaged. Industry standard numbers for electronics even 30 years ago
said electronics must work just fine even when lamps are at only 50%
intensity. But again, I am not just making a statement. One who even
designed this stuff has also provided numbers AND directs you to read
those numbers before knowing anything.

That 'whole house' protector is a strongly recommended item for all
homes - a very good and inexpensive item to have installed. Effective
if properly installed. But that 'whole house' protector did not
correct (what sounds like) an open neutral problem. That problem is
solved (for example) by retightening screws. That problem is but
another reason why building earthing is so critical to protect human
life.

===============================================
Vague -- earthing a building makes an open neutral hazardous because
now an arc can leap from either line or neutral to explose metalwork.
Contrary to popular belief the greatest danger to human life from electrical
causes is not electrocution (which is usually merely unpleasant) but fire
resulting from faulty connections or poor insulation.
Across the pond, neutral and ground (earth) are the same, the step-down
transformer is often on a pole with grounding connected directly to the
consumer, unlike the UK standard. The operating voltages differ too,
with lower voltages but higher currents in the USA.
US: http://aaenvironment.com/Electricity/TransformerOnUtilityPole.jpg
UK: http://tinyurl.com/6rc6wo

For more detail see
http://en.wikipedia.org/wiki/Earthing_system
===============================================



Nobody wants AC voltage to vary more than 10% constantly. Variation
means a slowly failing part will get worse. Harmful failures occur
later. Current voltage changes do not adversely affect industry
standard computers. Solution is not to install protection from
something that is not destructive. Solution is to correct the reason
for voltage variation before those variations become harmful - and
then start causing even premature light bulb failures.

On Nov 19, 8:03 am, jmfbahciv <jmfbahciv@aol> wrote:
west...@xxxxxxxxx wrote:
I didn't want my computer power supplies to have a variation of
+_15 volts twice a minute. They were not built for that
kind of abuse (this was in olden days when one computer was iron
boxes that would fill a gymnasium). The peripherals and TTYs
were spec'ed to be used in industrial-strength environments
and not the poofy power environment of a household.
,,,

I'm not talking about startup. I'm talking about the cycling when
using the device. At some point, it will not cycle up because
it's been "worn out" by the AC.
,,,

I wasn't the one who was confused. :-) I did write that the
electrician called it a power conditioner. He got the term
(I think) from the guy who sold him the widget. It worked
so well, that this guy put one in his house.

I did notice that, when the power was going to shut down, the
lights no longer grew really, really bright just before the
power went off. that kind of surge can also wreak havoc
with electronics.


.

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