Why is PC chasis put on voltage when earth/ground wire is missing ?!?

[Skybuck Flying]

Hello,

Apperently PC's have "incoming netfilters/powerfilters" in the Netherlands
possibly Europe which filter out fluctuations caused by other equipment on
power lines.

One design which seems to be in use is a netfilter which tries to use the
earth/grounding wire to get rid of the excessive fluctuations... however if
the earth wire is not available it seems to dump the additional voltage to
the chasis, or it puts the chasis under/on voltage for some other reason ?!?

So my question is:

Does the netfilter indeed output excessive voltages onto the chasis ?

If so why does it do this ?

Can it not simply dump the excessive fluctuations to the other wire ?

Perhaps it does not know which wire to use because of the way plugs can be
plugged in ?
(+ - versus - +)

If so then that could explain why it can't dump additional voltage to the
2-wire system and instead choses to dump it to the chasis.

Can this voltage on the chasis slowly build up over time ? Does it become
like a battery or something ?

However if these are not the reasons to put the chasis under/on voltage then
what is the real reason to put the chasis on voltage in case there is no
earth wire ?!?

Bye,
Skybuck.

 

[tuinkabouter]

Op 5/15/2011 12:29 AM, Skybuck Flying schreef:

Hello,

Apperently PC's have "incoming netfilters/powerfilters" in the Netherlands
possibly Europe which filter out fluctuations caused by other equipment on
power lines.

One design which seems to be in use is a netfilter which tries to use the
earth/grounding wire to get rid of the excessive fluctuations... however if
the earth wire is not available it seems to dump the additional voltage to
the chasis, or it puts the chasis under/on voltage for some other reason ?!?

So my question is:

Does the netfilter indeed output excessive voltages onto the chasis ?

If so why does it do this ?

Can it not simply dump the excessive fluctuations to the other wire ?

Perhaps it does not know which wire to use because of the way plugs can be
plugged in ?
(+ - versus - +)

If so then that could explain why it can't dump additional voltage to the
2-wire system and instead choses to dump it to the chasis.

Can this voltage on the chasis slowly build up over time ? Does it become
like a battery or something ?

However if these are not the reasons to put the chasis under/on voltage then
what is the real reason to put the chasis on voltage in case there is no
earth wire ?!?

hey moron,

This is already answered in another group you posted too.
Besides that YOU mentioned a website with the answers.

 

[Skybuck Flying]

Op 5/15/2011 12:29 AM, Skybuck Flying schreef:

hey moron,

Hey Moron,

This is already answered in another group you posted too.
Besides that YOU mentioned a website with the answers.

No LOL.

These websites explained why there was a voltage on the chasis from a
reverse enginering point of view.

My question is from a design point of view.

Why was it designed like this in the first place ?!

Bye,
Skybuck.

 

[Skybuck Flying]

Simply: regular netfilters contains two capacitors of the same value (the
so called Y-capacitors). The midpoint (fig. 1
http://www.ce-mag.com/archive/2001/janfeb/Georgerian36.html ) is connected
to the chassis. These capacitors carry about 0.25 -0.5 mA ~ current. Both
the ~ terminals in the PC are floting. As the mains outside the PC is
grounded, and in case the chassis of the PC is not connected to ground,
the chassis will, because of voltage dividing, end up at a potential of
half the mains voltage, capable of delivering 0.5 mA. So you can get a
shock when touching a not grounded PC. Especially care is needed if more
than one device with such a filter is connected to the same outlet.
Currents add up an can become hazardes.
So don't use your lips to sense the temperature somewere in the PC as I
sometimes did .

This was already discussed, this is looking at it from an reverse enginering
point of view.

Now the question is:

Why was it designed this way ?!?

Cannot it now be designed in a different way so that the chasis does not
need to be under/on voltage ?!?

Bye,
Skybuck.

 

[Ben]

This was already discussed, this is looking at it from an reverse
enginering point of view.

Now the question is:

Why was it designed this way ?!?

Cannot it now be designed in a different way so that the chasis does not
need to be under/on voltage ?!?

Bye,
Skybuck.

Read the fucking manual.

This apparatus MUST BE EARTHED !

So, connecting to a Non Earthed AC source is totally on your own risk.

 

[Skybuck Flying]

Read the fucking manual.

It's not in the fucking manual:

Seasonic S12 600 watt manual:

http://www.seasonicusa.com/images/BrochureManuals/NewS12Manual1.pdf

This apparatus MUST BE EARTHED !

Why does it need to be earthed ? Why does it need a third earth wire ?

Why cannot it not simply use two wires without earth and without putting the
chasis under voltage ?!?

Why does it need to put the chasis under voltage when it's not earthed ?

You have not answered any of my questions and seem to think that these
questions are documented somewhere which so far appears not to be the case.

Bye,
Skybuck.

 

[Skybuck Flying]

Antec 1200 case does not mention it as well:

http://www.antec.com/pdf/manuals/1200_EN manual.pdf

I am starting to get a little pissed off right about now.

There is no way I could have known that first of all earthing is required
and second of all what would happen if it's not earthed... -> chasis under
power.

Seems to me these companies might be sueable... only thing which is in doubt
if it was in the law by the time I bought and assembled and damage the PC...
(laws might have been updated in 2001 however might not apply to every home
build before that time).

Perhaps law says: "it's required to earth computers"... in that case the
companies might get away with it.
However law also says what to do when not earthed, though to difficult for
me to tell.

But perhaps not because I did not know what would happen if it was not
earthed and that if I would connect my devices that there would be a voltage
on the chasis:

Thus negleance of critical information and thus perhaps sueable for
withholding critical information which could lead to damage.

Bye,
Skybuck.

 

[MassiveProng]

There is no way I could have known that first of all earthing is required
and second of all what would happen if it's not earthed... -> chasis under
power.

Yes there is.

You let ONLY QUALIFIED, TRAINED persons perform the work.

If YOU are unaware of residential, commercial, industrial, and
technological STANDARDS, then you should not "dive in" and merely hope
all will be well, then proceed to blame others when YOU are the asshole
that fucked up.

The bloody shame is that you are so bloody fucking stupid.

 

[Martin Brown]

Hey Moron,


No LOL.

These websites explained why there was a voltage on the chasis from a
reverse enginering point of view.

My question is from a design point of view.

Why was it designed like this in the first place ?!

In any civilised country it is labelled in *VERY* LARGE LETTERS:

WARNING: THIS APPLIANCE MUST BE *EARTHED*

Ignore this safety instruction at your peril.

Failure to earth it results in the chassis floating at 120v or so but
realtively low current provided something else doesn't go wrong...

You are a third rate fuckwit and will surely electrocute yourself.

Regards,
Martin Brown

 

[Skybuck Flying]

If you do that, it becomes impossible to filter out "common mode"
electrical noise.

Care to explain why ?

To me these all seem wires... perhaps one or two wires with some kind of
voltage on them.

Let's suppose one wire with voltage on them and the other being zero/nul
wire.

What's the difference with a ground wire ?!? Some even say at nul wire could
be grounded as well.

So it seems to make little difference/sense... unless there is something
else going on like confusion about
wires/impossible to tell cheaply how they wired electronically and so
forth...

What makes the earth wire so special compared to the other wires ?!?

Bye,
Skybuck.

 

[Skybuck Flying]

Perhaps it's like a traffic jam.

The + is where the traffic comes from.

The - is where the traffic would go to.

The PC wants to consume some of the traffic and
wants to shed the rest so it would have to divert
traffic to the -.

However becomes other devices might also try to shed traffic to the -, the -
gets flooded and can't handle the traffic, so the traffic backsup back into
the pc and the pc gets into trouble.

Perhaps this is where the ground wire comes into play.

The ground wire is like an additional lane, which is at least as big as the
+ maybe even bigger so it can easily divert extra traffic.

At first this might not seem to make much sense since how could the - be
bigger than the + ?

Well that's where batteries/capacitators come into play... they store some
of the + insight them... and then suddenly it's all released at once...
flooding the -.

Just like people parking their cars at work/parking garage... then all
leaving at the same time ! =D

Just another whacky theory/hypothesis of mine, does it make any sense ?

Bye,
Skybuck.

 

[Skybuck Flying]

Care to explain why ?

Not really, because ...

To me these all seem wires... perhaps one or two wires with some kind of
voltage on them.

... you've just demonstrated that you don't currently understand
enough about electricity, or mains-type wiring conventions, to make
much sense out of the answer.

Let's suppose one wire with voltage on them and the other being zero/nul
wire.

What's the difference with a ground wire ?!? Some even say at nul wire
could
be grounded as well.

What makes the earth wire so special compared to the other wires ?!?

There is a real difference. You're going to have to figure this one
out for yourself.

Simply apply one of the most fundamental laws of electricity - Ohm's
Law:

E = I * R

Consider the fact that there are often many amperes of current (I)
flowing through both the hot and neutral ("nul") wires.[/QUOTE]

Flowing in what direction ?

Also consider that the safety-ground wire is *not* carrying any
current under normal circumstances.

I don't agree with that simply because all pc's attached to it are "leaking"
even if it's just a little bit.

So if this is compared with a nul-wire which some say has little to no
current as well I see little difference.

At least from the wire perspective... perhaps the Earth is a big sucking
device sucking all the electricity harder
on the ground wire then on the other wires but I don't know that for sure

Finally, consider the fact that all wires have resistance.

I'd figure all wires made of same material and same thickness ultimately so
perhaps little difference ?

At least the wires directly on the socket... the ground pin does seem a bit
thicker

Now, answer it for yourself: what's different between the ground-wire
connection and the neutral-wire connection when they reach your PC?

Depends on situation... neutral wire could be 0 or -120 volts, ground should
be 0 or something... but can also contain some... perhaps 120 volts leaking
from pc !

The neutral wire probably has more ampere flowing because of the pc... and
the ground wire has little ampere flowing...

But why can't excessive ampere not simply flow out the neutral wire ?!? why
most it go through ground wire ?!?

Why would ground wire have less fluctuations ? Partially answered already
because leak is only very little...

But why would leaking to neutral cause fluctuations ?! Seem my traffic
reasoning... perhaps that has something to do with it...

Eletricity does flow in a certain direction... from + to - ?!?

So big + goes to PC... which goes to -.

Little + is leak and why can't it also go to - ?!?

Perhaps use eletricity consuming component to get rid of it, instead of
going via ground wire ?!? So ground no longer necessary.

Don't bother with formula's and such... nature don't work with formula's...

Nature work with electrons... so you try explaining it with little
electronics as if they were cars...

Maybe then I will understand it a bit better !

Bye,
Skybuck.

 

[Martin Brown]

Care to explain why ?

To me these all seem wires... perhaps one or two wires with some kind of
voltage on them.

Let's suppose one wire with voltage on them and the other being zero/nul
wire.

What's the difference with a ground wire ?!? Some even say at nul wire could
be grounded as well.

So it seems to make little difference/sense... unless there is something
else going on like confusion about
wires/impossible to tell cheaply how they wired electronically and so
forth...

What makes the earth wire so special compared to the other wires ?!?

It is the one that saves your worthless life when something goes wrong.

PSUs can be designed to run off 2 pin sockets if they are double
insulated and show a square in a square on the outside. Wallwarts and
mobile phone charges and portable PC PSUs are typically of this type.

All the others are intended to be used in an earthed chassis
configuration to protect the user from any live to case faults - for
example if one of the capacitors breaks down and fails short circuit.

I find it incredible that anyone can be so monumentally dumb.

Regards,
Martin Brown

 

[Bob F]

Flowing in what direction ?

It's AC, so it flow both directions.

I don't agree with that simply because all pc's attached to it are
"leaking" even if it's just a little bit.

So if this is compared with a nul-wire which some say has little to no
current as well I see little difference.

At least from the wire perspective... perhaps the Earth is a big
sucking device sucking all the electricity harder
on the ground wire then on the other wires but I don't know that for
sure

I'd figure all wires made of same material and same thickness
ultimately so perhaps little difference ?

At least the wires directly on the socket... the ground pin does seem
a bit thicker

In some cases, the ground wire is somewhat smaller than the power conductors.

Depends on situation... neutral wire could be 0 or -120 volts, ground
should be 0 or something... but can also contain some... perhaps 120
volts leaking from pc !

The neutral wire probably has more ampere flowing because of the
pc... and the ground wire has little ampere flowing...

Neutral carries almost exactly the same current as the hot lead.

But why can't excessive ampere not simply flow out the neutral wire
?!? why most it go through ground wire ?!?

Why would ground wire have less fluctuations ? Partially answered
already because leak is only very little...

But why would leaking to neutral cause fluctuations ?! Seem my
traffic reasoning... perhaps that has something to do with it...

Eletricity does flow in a certain direction... from + to - ?!?

Remember, this is AC (alternating current). It goes one way, then the other,
ovewr and over.

So big + goes to PC... which goes to -.

Little + is leak and why can't it also go to - ?!?

Perhaps use eletricity consuming component to get rid of it, instead
of going via ground wire ?!? So ground no longer necessary.

Ground is there to carry minor leakage (to get rid of electrical noise) and
contain major fault currents, thus keeping the chassis at a safe voltage level
even if something goes wrong, so you don't get electrocuted. The chassis stays
at ground voltage, the same as your house pipes, floor, etc.

Don't bother with formula's and such... nature don't work with
formula's...
Nature work with electrons... so you try explaining it with little
electronics as if they were cars...

Maybe then I will understand it a bit better !

Bye,
Skybuck.

Try googleing a few basic electronics sites and learning. The formulas show
exactly how electricity works - don't put them down. When you understand them,
you will understand how it works. Argueing with people here ("don't bother with
formulas") just shows an unwillingness to study and learn. You seem to want us
to do all the work for you to learn.

 

[Skybuck Flying]

Remember, this is AC (alternating current). It goes one way, then the
other, ovewr and over.

Hmm interesting point... I'll look into this to make sure it's true... but
it sounds believable !

But how such a large distance can swing/move both ways remains weird to
me... then again there are transformer
houses and other stuff in between... and how stuff can swing both ways
between multiple homes also seems a bit weird.

Then it must be flucuating a lot me thinks... like multiple waves right
behind each other... otherwise if it was a single super large wave it would
surely get disturbed

Ground is there to carry minor leakage (to get rid of electrical noise)
and contain major fault currents, thus keeping the chassis at a safe
voltage level even if something goes wrong, so you don't get electrocuted.
The chassis stays at ground voltage, the same as your house pipes, floor,
etc.

This is assuming the grounding from the chasis to the earth is the shortest
path...

But if I touch my pc and the path through me is shorter will it still go
through me ?!?

Or does it depend on the "most" resistance... if I offer more resistance
then electricity would go via wires ?!?

Or does "literally" shortest distance win... hmmm...

And does electricity care about my resistance anyway ?! probably not up
to a certain point, probably depends on current.

Try googleing a few basic electronics sites and learning. The formulas
show exactly how electricity works - don't put them down. When you
understand them, you will understand how it works. Argueing with people
here ("don't bother with formulas") just shows an unwillingness to study
and learn. You seem to want us to do all the work for you to learn.

I am trying to learn, but I want to learn it from a practical and
conceptually point... not from a theoretical point... that's more for people
wanting to do real designs and such... Perhaps later I will look into
formula's a little bit more... but don't count on it ! =D

Bye,
Skybuck.

 

[Skybuck Flying]

It is the one that saves your worthless life when something goes wrong.

PSUs can be designed to run off 2 pin sockets if they are double insulated
and show a square in a square on the outside. Wallwarts and mobile phone
charges and portable PC PSUs are typically of this type.

Oh so according to you it is possible to make psu's run on just two wires ?!


Hmmm

But something tells me this won't work well or would be dangerous, perhaps
because
they banned ?

Will they also "scale" up to 600 watt or are these only suited for 200 watts
?!?

All the others are intended to be used in an earthed chassis configuration
to protect the user from any live to case faults - for

How Ironic "to protect user from live"... well now they putting "live" on
chasis when not grounded.

Don't you think that's kinda ironic and dangerous ?!

example if one of the capacitors breaks down and fails short circuit.

Yeah that's my worry right now... what if it breaks and how easy is it to
break ?!?

What will it take to break it ?!? External surges ?!?

I find it incredible that anyone can be so monumentally dumb.

Well you not very smart either... you just stated some things... but have
not explained why a two pin psu would be possible.

Some claim that might not be possible.

Bye,
Skybuck.

 

[personaobscura]

Hmm interesting point... I'll look into this to make sure it's true... but
it sounds believable !

But how such a large distance can swing/move both ways remains weird to
me... then again there are transformer
houses and other stuff in between... and how stuff can swing both ways
between multiple homes also seems a bit weird.

Then it must be flucuating a lot me thinks... like multiple waves right
behind each other... otherwise if it was a single super large wave it would
surely get disturbed

[...]

Oh my.

Just when you think this SkyFuck guy couldn't get any stupider, he exceeds all
expectations.

With any luck at all, he'll get his Darwin Award. Posthumously, of course...

 

[Bob F]

Hmm interesting point... I'll look into this to make sure it's
true... but it sounds believable !

But how such a large distance can swing/move both ways remains weird
to me... then again there are transformer
houses and other stuff in between... and how stuff can swing both ways
between multiple homes also seems a bit weird.

Then it must be flucuating a lot me thinks... like multiple waves
right behind each other... otherwise if it was a single super large
wave it would surely get disturbed

In the US, residential power is typically 240 Volt AC. That is through two
wires, and is two sine waves (look it up) 180 degrees out of phase.
Additionally, there is a groundwire that is grounded where it comes into your
house. The two power "phases" are 180 degrees out of phase with each other. When
one reaches +120V, the other reaches -120V. Thus, the voltage difference between
them is 240VAC (volts alternating current) "peak to peak". They both reach zero
volts at the same time, crossing in different directions. The 120V houshold
outlets are connected between one of the power leads and "ground" (the neutral
wire), so they only carry 120V of the total 240V available. "Super Waves"? I
guess so. But, 2 of them in different conductors, 180 degrees out of phase, or
one "single phase 240V varying equaly around ground, depending on how you look
at it.

If you touch one of the wires of a 240VAC circuit, you are only getting a 120VAC
shock. You have to touch both to get 240VAC.

This is assuming the grounding from the chasis to the earth is the
shortest path...

But if I touch my pc and the path through me is shorter will it still
go through me ?!?

Or does it depend on the "most" resistance... if I offer more
resistance then electricity would go via wires ?!?

Or does "literally" shortest distance win... hmmm...

And does electricity care about my resistance anyway ?! probably
not up to a certain point, probably depends on current.

Yes. It cares about your resistance. The current through you would vary
indirectly with the ratio of the resistance through you (high) to the resistance
through the ground wire (low). So you get very little current, if you have a
good ground. Worst case, you would get 1/2 the line voltage if it shorted
directly to the chassis attached to the ground wire, but only until the breaker
pops.

I am trying to learn, but I want to learn it from a practical and
conceptually point... not from a theoretical point... that's more for
people wanting to do real designs and such... Perhaps later I will
look into formula's a little bit more... but don't count on it ! =D

Bye,
Skybuck.

http://www.allaboutcircuits.com/vol_2/chpt_1/1.html

See "phase shift = 180 degrees" - This is what the two wires in 240V ac are
doing relative to each other.
http://www.allaboutcircuits.com/vol_2/chpt_1/5.html

Wow! I sure wasted too much time on this.

 

[Chieftain of the Carpet Crawlers]

TWO pin power supplies are quite possible

NOT in a PC they aren't, you fucking total retard!

 

[Martin Brown]

NOT in a PC they aren't, you fucking total retard!

Almost all portable PCs use two pin mains adapters as an external brick,
and there is no reason why some of the micro PCs can't do it that way
either.

Desktops usually use cheap and nasty high power switching supplies in a
metal chassis case which any sensible person would earth.

The fact is that skybuck is below moron level of intelligence and the
best we can hope for now is to persuade him to grab firm hold of an
earthed water pipe and his PC at the same time.

With a bit of luck he won't waste our time again after that ;-)

Regards,
Martin Brown