Perils of floating ground (no ground) on your PC...what are they?

Inspired by my other post (where BTW my mobo has now failed) and the below blurb by Paul from another thread, I wonder what are the perils of floating ground, that is, no ground at all? I notice there is no ground wire here in southeast Asia (I guess you could build one, and I hope hospital buildings have one, but it would not completely, totally shock me--no pun intended--if even these places did not have a ground, though I would imagine the better hospitals do).

I think the effect would be constantly abused electronics. I buy UPS (uninterrupted power supply), even by Belkin (hard to find, they compete in price here in the Philippines and you have to settle for cheap Chinese counterfeit designs, and once my Belkin was used up--more on that below--I could not find a replacement battery), but they only last about a year, until the numerous power surges (you can sometimes even see them, as the lights brighten) and/or lightening strikes (it rains here like crazy, as Flasherly can tell you) ruin them. (utilities outside of Manila's Meralco, which actually has a decent international reputation, though they are overpriced as all are here due to frequent electrical meter thefts that have to be paid by the power company customers, are very spotty, and power shortages--called 'brownouts'--are about once every three days lasting about an hour but during typhoons they can last for days and sometimes even a month in the rice paddy countryside). Then you must get a replacement battery (hard to find) or buy a new UPS. But all the while your PC can be affected, if the UPS does not have a AVR (automatic voltage regulator), which I think (suspect?) the cheap UPS do not (instead they use surge protectors I would imagine, and probably the capacitors on the surge protectors are too small to do the job properly).

What to do? Should I get an AVR and the plug a UPS into it? Is that better protection? Do I rely on the built in buffers in my PC tower power supply? I notice BTW my old (2010) Lenovo ThinkPad laptop does not suffer any problems, as it was well built with quality components and has its own transformer built in. It's the cheap tower I bought here that is constantly being repaired (which I don't use for mission critical stuff, just programming and gaming).

Also keep in mind what I've said befo ALL (and I mean all) 'new' equipment sold in the Philippines is defective or refurbished. ALL. Even "new" cars are lemons (even small lemons but nevertheless rejects) from the West. There are NO exceptions to this rule. Every single person I know has stated this and I've also experienced this. If I want 100% virgin new equipment I ask my friends and relatives in the USA to mail me the equipment and a month later I pay a small $5 gift tax (if it's mailed from a company not a friend however you must pay a huge import duty, often 100% of the purchase price) and it's mine.

Paul?

RL


There is a reason [why USB ports in the front panel seem to fail more than the back, which is also my experience--RL], but I didn't want to write it up.

It has to do with the plastic front on the computer.

When you dump ESD into a front panel USB, it can't
"drain" into the chassis directly. The ESD discharge
goes down the front panel USB cable, down the ground
of it. And while doing so, the wire is in parallel
with D+ and D-, inducing high voltage in those leads
too.

Whereas the rear connectors are beautifully designed.
The area around the connector has metal, the metal makes
contact with the chassis. The spring fingers on the I/O plate,
provide a conduction path between the chassis and the connector
body. The "parallel" run of wires in that case, is very short.

If you're lucky enough to have a PC with a metal fascia
on the front, then there would be an opportunity for some
of the ESD energy to go into the chassis, instead of
near the wires.

Using plastic on the front of the machine, allows the
manufacturer to make complex aesthetically pleasing
shapes with minimal work. If the front was
fabricated out of metal, the box would likely
look more ugly that it already is.

ESD protection for equipment is a complex subject. Some
designers, their first approach is to insulate everything
on the front, if possible. (So the user can't zap anything.)
If you're putting I/O connectors on a surface, that idea
is ruined right away. The next approach after that, is to
"drain" to chassis. Even this can be problematic in terms
of upset. We had a system, where every time there was the
least contact between computer metal and metal chairs or
objects in the room, the box would reset. And there was an
actual reset wire inside the computer, picking up energy by
induction. Once that was improved, the problem stopped. I
got a free plane flight to a customer site, to observe that
one happening, and it was plenty freaky. The amount of signal
required to upset the computer was amazingly small. You could
fart, and that computer design would reset itself, and all
because some clever person left a long run of reset wire
(no twisted pair) inside the box.

We test systems like that at work, with an ESD probe
modeling the Human Body Model. It includes an RC time
constant, and you charge to "X" volts and do your test.
The equipment will have "upset" and "damage" ratings,
at two different voltages. So maybe the spec says
it cannot reset if hit with 5kV of discharge, or
it cannot be damaged if hit with 10kV. The probe has an
insulated handle, and a rounded tip to avoid corona.
And then you bring it up to the equipment and zap it,
and test whether your protection design is working.
We had *many* failures with the "metal draining" method,
requiring analysis of where the discharge was going. In
some cases, spring fingers being added to some metal things,
to encourage high voltage discharge to go down a
certain path.

I never had to get involved in that stuff for what I was
building (never ran the HV probe myself), but I was around
while the other staff were working on it (multiple projects).
So got to discuss the approach they were using. Fun stuff.
And we never had incidents of staff zapping one another with
the probe. True professionals :-) Just to prove the probe
was actually modeling HBM, and gave a human amount of
static-like discharge.

Intel USB ports are rated for around 5-6kV of ESD (written up
in the Intel Journal). RS232 ports (good ones), are rated
for 15kV, and those were the first chips to be recognized as
having a problem, and the redesign of those was excellent.
Regular chips (where the wires don't go near humans) are
rated for 1kV or so. For third party USB, like NEC brand,
I have no idea what their rating is, but it's probably not
as high as Intel. Some PCI Express slots are extremely sensitive,
and could well be 1kV or less (there were some early PCI Express
designs, where customers blew out the PCI Express slot during
their equipment build). On those systems, once alerted to that
fact, you'd want your ESD strap while assembling computers
based on those boards. Since I'm no longer hearing that
complaint, I guess the chipset makers have figured that out.

It's possible to add protection networks to electrical items
externally. But this topic is more art than science, and the
vast majority of available solutions for it are crap. I
worked with a gentleman, who tirelessly tested this stuff.
Even when not tasked with a design, he would get samples
of components like this and test them. The critical parameter
is stray capacitance, and good components (1pF or less) are
hard to find. Some of the good solutions, were coming
from small companies (startups), and not from the
larger suppliers. You cannot put these on high
speed signals, unless the stray capacitance is
extremely low. Which rules out most of the ones
you see advertised.

http://www.eetimes.com/document.asp?doc_id=1275127

Paul

On Tue, 23 Jun 2015 20:01:00 -0700 (PDT), RayLopez99
wrote:

I think
the effect would be constantly abused electronics. I buy UPS
(uninterrupted power supply), even by Belkin (hard to find, they
compete in price here in the Philippines and you have to settle for
cheap Chinese counterfeit designs, and once my Belkin was used
up--more on that below--I could not find a replacement battery), but
they only last about a year, until the numerous power surges (you can
sometimes even see them, as the lights brighten) and/or lightening
strikes (it rains here like crazy, as Flasherly can tell you) ruin
them.

--

Huge crackle and then the big boom gets lowered. Was out in one just
this afternoon. No sooner got a wheelbarrow full of tools wheeled out
and setup for finishing up a fence, making the gate, when it started
coming down in buckets. Sure enough, both computers were reset.

I like these two Gigabyte boards I'm running, both in AMD/Intel,
last-generation socket quadcore configs. They've a bit of extra
engineering "heft," hopefully for that sort of thing. Or so Gigabyte
advertises.

Couple hardcore friends mentioned how they considered approaching
stormy climate conditions.

One liked gas discharge tubes (I took the impression it was larger
physical apparatus for hooking up to the building mains)...
http://www.littelfuse.com/products/g...rge-tubes.aspx

Another said he liked this approach in a one-to-one transformer...
https://en.wikipedia.org/wiki/Isolation_transformer

A direct lightning hit, I figure, I'm at least somewhat more isolated
from a likelihood to experience, in a denser populated area and at
some distance from known local geographic "storm highways," which
traditionally sustain more damage from Acts of God.

The brown- & black-outs, however, everyone experience. Medical and
essential public service centers of course go elaborate with
generators and such, whereas a common though essential business
viewpoint might variously suffice with a UPS unit.

I'd rather put money in a UPS than surge suppression devices, given my
specific locale and reasoning, although after years of this stuff,
good gear is as much a fallback, a good power supply and motherboard,
aggressively engineered and spec'd for dealing in some leeway for
electrical faults from utility power grids.

Not that given enough of it -- there are storms, and then there are
some storms that never seem to end -- and I'll shut it all down until
things clear up. Least around here, powering something back up that's
about due, perhaps substandard, and not gear especially which cares to
power up, is *very likely* to occur after being subject to electrical
storm/power grid operational irregularities.

RayLopez99 wrote:
Inspired by my other post (where BTW my mobo has now failed)
and the below blurb by Paul from another thread, I wonder what
are the perils of floating ground, that is, no ground at all?
I notice there is no ground wire here in southeast Asia (I
guess you could build one, and I hope hospital buildings have
one, but it would not completely, totally shock me--no pun
intended--if even these places did not have a ground, though
I would imagine the better hospitals do).

The effect of the missing safety ground, is "between the island
of your computer gear" and "the outside world". It's mostly an
issue of annoying shock sensation, when touching the computer
chassis or when touching the chassis of a peripheral.

It's not an issue for the AC electrical system. Makes no
difference to it.

It makes a difference to "fault analysis". But when is the
last time someone had a hard fault between 220 Live terminal
and the chassis of the computer. I can't remember the
last description of a line to chassis fault. There aren't
any. Just as nobody has come to the newsgroup, complaining
about being deaf from an exploding main capacitor inside
the ATX power supply. Certain kinds of faults that could
theoretically be an issue, aren't normally an issue.


I think the effect would be constantly abused electronics.

I don't view the Safety Ground issue that way. When you
connect a peripheral to the computer, the signal ground
of the cable makes contact first. And some of the I/O
standards, the power/ground pairs have longer contacts
than the signal pins. Which encourages safe connection,
even in the presence of a Safety Ground issue. So it's not
as bad a picture as you paint it.

It takes devious individuals, putting hardware at risk
on purpose (figuring out the best way to enhance the risk),
that's about the only way you can increase the risk. And for
typical logic devices, and the maximum spec level of leakage,
I still don't see this as a big deal.

I buy UPS (uninterrupted power supply), even by Belkin (hard
to find, they compete in price here in the Philippines and you
have to settle for cheap Chinese counterfeit designs, and once
my Belkin was used up--more on that below--I could not find a
replacement battery), but they only last about a year, until
the numerous power surges (you can sometimes even see them, as
the lights brighten) and/or lightening strikes (it rains here
like crazy, as Flasherly can tell you) ruin them. (utilities
outside of Manila's Meralco, which actually has a decent
international reputation, though they are overpriced as all are
here due to frequent electrical meter thefts that have to be
paid by the power company customers, are very spotty, and power
shortages--called 'brownouts'--are about once every three days
lasting about an hour but during typhoons they can last for days
and sometimes even a month in the rice paddy countryside). Then
you must get a replacement battery (hard to find) or buy a new
UPS. But all the while your PC can be affected, if the UPS
does not have a AVR (automatic voltage regulator), which I think
(suspect?) the cheap UPS do not (instead they use surge protectors
I would imagine, and probably the capacitors on the surge
protectors are too small to do the job properly).

There has been a trend, at least in car batteries, to add calcimu
to the plate material. On the one hand, this improves the rate of
self discharge, but it also happens to make the battery more
susceptible to damage from deep discharge. The UPS should
really shut off the load sooner, to preserve the long term
life of the battery.

Whether SLA batteries in UPS designs are affected by this,
I don't know. All I can tell you, is battery chemistry is
whimsical, and the companies that gross around 11 billion a
year making replacement batteries, they don't really care
if you're unhappy with the performance of your purchase.


What to do? Should I get an AVR and the plug a UPS into it?
Is that better protection? Do I rely on the built in buffers
in my PC tower power supply? I notice BTW my old (2010) Lenovo
ThinkPad laptop does not suffer any problems, as it was well
built with quality components and has its own transformer built
in. It's the cheap tower I bought here that is constantly being
repaired (which I don't use for mission critical stuff, just
programming and gaming).

People who run server rooms, use double-conversion supplies.
The kind of UPS that has a cooling fan, the inverter runs
all the time. The device goes AC-DC-AC, and the conversion
path is always in use. You can get those for maybe $400 to
$500 or so. They used to be $1000.

You can also get a UPS with a built-in AVR, but it's not
clear to me what kind of transient response those have. And
how they respond to certain kinds of "insults" on the line.
I can promise you, that with the right stimulus on the line
side of the UPS, the output of the UPS can be in worse
shape, than if the UPS was not present. The double-conversion
UPS is not nearly as bad in that regard, as the battery
functions as a filter.


Also keep in mind what I've said befo ALL (and I mean all)
'new' equipment sold in the Philippines is defective or refurbished.
ALL. Even "new" cars are lemons (even small lemons but
nevertheless rejects) from the West. There are NO exceptions
to this rule. Every single person I know has stated this and
I've also experienced this. If I want 100% virgin new equipment
I ask my friends and relatives in the USA to mail me the equipment
and a month later I pay a small $5 gift tax (if it's mailed
from a company not a friend however you must pay a huge import
duty, often 100% of the purchase price) and it's mine.

Paul?

RL

Your UPS issue is separate from your Safety Ground issue.

There are at least five kinds of UPSes. And price tiers.
They range from $50 to $1000 for "home" UPS solutions.
If I really thought I had an issue with power quality, and
the gear was so expensive I had to protect it, the double-conversion
type would be an intermediate solution.

(Look for ones with connectors for external battery packs,
if you need longer runtimes.)

http://www.newegg.com/Product/Produc...82E16842111448

The Safety Ground issue is primarily a "personal comfort" issue.
In terms of day to day experience. If there is ever an event, where
the ATX supply shorts out and the "hot" wire is joined to the ATX
chassis, that's when you would want the Safety Ground to be there
to shunt the line to ground and trip the breaker. Otherwise, the
chassis would remain very hot. But if events like that don't
happen, you get a tiny tingling sensation.

In terms of lightning issues, you still have wires in the line
cord, for the lightning to leap to and bridge. So the analysis
of lightning risk isn't all that much different. Equipment can be
blown up or destroyed, no matter how carefully you arrange
the cables. And lightning is fickle, taking a right angle
turn whenever it wants, blowing a hole through a wall, and
seeking out your favorite painting on the wall and burning
it to a crisp. While there are guiding principles, things
an engineer can do to "harden" a part of a household, in the
end it's all a matter of probabilities.

Paul

On Wednesday, June 24, 2015 at 7:48:18 PM UTC+8, Paul wrote:

Your UPS issue is separate from your Safety Ground issue.

There are at least five kinds of UPSes. And price tiers.
They range from $50 to $1000 for "home" UPS solutions.
If I really thought I had an issue with power quality, and
the gear was so expensive I had to protect it, the double-conversion
type would be an intermediate solution.

(Look for ones with connectors for external battery packs,
if you need longer runtimes.)

http://www.newegg.com/Product/Produc...82E16842111448

The Safety Ground issue is primarily a "personal comfort" issue.
In terms of day to day experience. If there is ever an event, where
the ATX supply shorts out and the "hot" wire is joined to the ATX
chassis, that's when you would want the Safety Ground to be there
to shunt the line to ground and trip the breaker. Otherwise, the
chassis would remain very hot. But if events like that don't
happen, you get a tiny tingling sensation.

In terms of lightning issues, you still have wires in the line
cord, for the lightning to leap to and bridge. So the analysis
of lightning risk isn't all that much different. Equipment can be
blown up or destroyed, no matter how carefully you arrange
the cables. And lightning is fickle, taking a right angle
turn whenever it wants, blowing a hole through a wall, and
seeking out your favorite painting on the wall and burning
it to a crisp. While there are guiding principles, things
an engineer can do to "harden" a part of a household, in the
end it's all a matter of probabilities.

Paul

Very interesting. FYI, re the other thread, it turns out the power supply (600 W "Ice-Man" from Korea) was defective. It was swapped for another 600 W PS. I was shocked that they don't even make 450 W PS anymore (the usual said the PC repair guy is 700 W for tower PCs). Also I mentioned that this was my third PS in as many years and he was not surprised, with the erratic voltage here in PH, and voltage surges, not to mention lightening strikes, saying I should buy a good UPS (his store sold some). I also have a theory that the UPS I use is constantly ON and possibly harmful to the PC, in that it's not grounded, so I intend to turn it OFF whenever I turn my PC off for the night. Don't know if that will help but I'll start doing that.

RL

On Wednesday, June 24, 2015 at 2:58:32 PM UTC+8, Flasherly wrote:

Not that given enough of it -- there are storms, and then there are
some storms that never seem to end -- and I'll shut it all down until
things clear up. Least around here, powering something back up that's
about due, perhaps substandard, and not gear especially which cares to
power up, is *very likely* to occur after being subject to electrical
storm/power grid operational irregularities.

Thanks Flasherly. Sounds almost like your back in Thailand

Gas discharge tubes...wow, I didn't know they still make them for the consumer market, I thought they went out with the vaccumm tubes, but I see they have a use.

RL

On Wednesday, June 24, 2015 at 7:48:18 PM UTC+8, Paul wrote:

You can also get a UPS with a built-in AVR, but it's not
clear to me what kind of transient response those have. And
how they respond to certain kinds of "insults" on the line.
I can promise you, that with the right stimulus on the line
side of the UPS, the output of the UPS can be in worse
shape, than if the UPS was not present. The double-conversion
UPS is not nearly as bad in that regard, as the battery
functions as a filter.

I was thinking this as well, that's why I intend to turn off the UPS at night since I'm not sure if the constant voltage in is beneficial. Also, I notice a lot of problems seem to start whenever the UPS 'kicks in'. Problems such as HDD going bad shortly thereafter, Power Supplies on the PC going bad, etc. Probably a coincidence however. And I'm not sure this cheap UPS is any better than just a cheap surge protector. Sad but true. However it does work in keeping the PC alive during a power outage long enough for you to save your work and gracefully shut down (that's why I bought it, so I don't lose any programming code when I'm compiling something and there's a power outage, which happens due to Murphy's Law).

RL

On Wed, 24 Jun 2015 08:31:25 -0700 (PDT), RayLopez99
wrote:

Thanks Flasherly. Sounds almost like your back in Thailand

That fence, it was like three fences. Eight-foot board-on-board
sections coming out, at 100-150lbs each, and six-foot lightweight
vinyl going in, but of course requiring all new post holes;- the
"third fence" is effectively having to tear down the wood with a
circular saw and into small sections for curb placement and a
carry-off.

One person, me. Effectively three wood sections replaced during the
course of a day for 30 sections total.

Brutal as it is standing in the sun, when, in Thailand, the sun goes
down, but it's actually as if doesn't, not until a couple hours past
sunset;- The sun goes down here and it feels physically perceptible.

....However many miles offset in differences are to be placed directly
on the equator, from the savannahs and where I am.

Like Thailand, I can go, here, without air conditioning, and the state
of that fence is the result of seven hurricanes, mostly, that occurred
during one summer, variously to ravage property.

And I can hear it now outside, the crackling thunder just now as it's
starting again.

What ****es me off is the many times I've forgotten to paste and copy
this far, hotkeyed into a physical disc sector hardcopy, henpecking
something out off keys, shifting accents. . .when boom! and suddenly
it's gone, lost, everything said so far, to try or much less want then
to rewrite after abruptly so plunged into an electrical black pit.

-
Electrostatic ether will shorten a movement through time.

My Main PC is also ungrounded.

And it's been working pretty nice...

Very rarely though there are very strange electrical issues...

Monitor will fail to come on... sometimes even the PC.

I solve this issue, by disconnecting all cables and then waiting one or two
minutes, and then re-plugging all, sometimes this is repeated.

Recently the cable modem adapter was also overheating.

However I think this issue has now been solved.

The ISP has stores where adapters can be exchanged for free for new ones.

The electric guy told me... these newer adapters have bigger copper coils in
them... to prevent overheat.

However he has also been receiving worse adapters, if I remember his story
correctly.

I guess it has to do with the rising price of copper... copper is getting
expensive... possibly because of copper mine strikes or so... or copper
speculation.

Anyway it seems I have exchanged a new one just in time... I just checked it
the cable modem adapter's heat... and it's slightly warm... a big
improvement... from the very hot adapter.

In the past my PC died probably mostly from overheat... kinda funny to read
your story about all that water

My motherboard has overheat protection... not so long ago I cleaned my PC
from dust... this helps a lot.

I placed the Scyth Ninja (?) cpu cooler in such a way that air flushes in
from the front directly between it's heat fins...

I think this leads to somewhat better cooling but the drawback is... dust
particles will sufficiate/clutter this heatsink opening much faster.

Perhaps placing heatfins side ways... would be better... to prevent dust
build up... but for slighty worse cooling properties.

Remarkably enough the GT 520 graphics cards heatsink have no problem with
dust build up... ofcourse there is also no fan on it... it's passively
cooled..

While the cpu heatsink needed a major cleaning... so I did that...
especially since I noticed the PC would go offline with even a small little
work from a game.

Since it's summer a clean/dust out was necesary... and now my PC ran run
fine even at room ambient temperatures of 26 degrees celcius or so perhaps
higher...

So that makes me happy and feel easy/relaxed !

Cool to hear from developing countries (?) ! =D

I wish you the best with getting your PC running up 24/7 non stop !

I do consider programming and gaming "main" tasks though lol

Bye,
Skybuck =D