Unplug the power supply?

  • Thread starter Thread starter hdtv guy
  • Start date Start date
You're all wet. Ground is ground is ground. Static electricity is no
different that any other electricity.
If you unplug it you also remove the ground. Leave it plugged into a
power strip and turn off the power strip.
Click to expand...

If electrically correct, then a good place to ground a lightning rod
is to a computer chassis. Since ground inside a TV is same as ground
beneath your feet, then go ahead. Touch that TV ground. Pain from an
electrical shock demonstrates why two grounds are completely
different; why one ground is called a floating ground and not called
earth ground,

Motherboard ground is difference from wall receptacle safety ground;
is different from breaker box ground; is different from earth ground;
is different from telephone wiring ground; is different from chassis
ground; is different from any ground created by water pipes.

No grounding of electrical devices may be performed by water pipes.
Doing so can even threaten human life in a bathroom. Any ground
connection to water pipes only removes electricity from those pipes.
This requirement is a major safety code change. Grandfathering is the
only reason some safety grounds to water pipes can exist. And again,
a ground also called water pipes is electrically different from all
those other grounds.

Knowledge of basic electricity means that electricity is always
different at two ends of a wire. Sometimes that difference is so
minor as to be considered same. But two ground connected at two ends
of a wire are electrically different. Why do many electronic devices
contain separate analog and digital grounds? But again, two grounds
that are interconnected are also electrically different. Different
grounds even when interconnected are electrically different.

Returning to this thread's point. Earth ground has no relevance to
the ground for a static electric discharge circuit. An electric
circuit from leg, through arm, through computer chassis, through
table, and to bottom of shoe. Earth ground exists where in that
circuit? No where. Earth ground does nothing for semiconductor
static protection. One here has assumed motherboard ground is same as
earth ground.
Ground is ground is ground.
Click to expand...
Hardly.

Without or without earth ground connected to a computer, a static
electric discharge from finger to semiconductor will damage (or over
stress) that semiconductor. (Over stress is another relevant
concept.) Where is protection provided by earth ground? Non-
existent. Earth ground or safety ground (also called equipment ground
because it is different from earth ground) do nothing for static
electric protection.
 
w_tom said:
If electrically correct, then a good place to ground a lightning rod
is to a computer chassis. Since ground inside a TV is same as ground
beneath your feet, then go ahead. Touch that TV ground. Pain from an
electrical shock demonstrates why two grounds are completely
different; why one ground is called a floating ground and not called
earth ground,

Motherboard ground is difference from wall receptacle safety ground;
is different from breaker box ground; is different from earth ground;
is different from telephone wiring ground; is different from chassis
ground; is different from any ground created by water pipes.

No grounding of electrical devices may be performed by water pipes.
Doing so can even threaten human life in a bathroom. Any ground
connection to water pipes only removes electricity from those pipes.
This requirement is a major safety code change. Grandfathering is the
only reason some safety grounds to water pipes can exist. And again,
a ground also called water pipes is electrically different from all
those other grounds.

Knowledge of basic electricity means that electricity is always
different at two ends of a wire. Sometimes that difference is so
minor as to be considered same. But two ground connected at two ends
of a wire are electrically different. Why do many electronic devices
contain separate analog and digital grounds? But again, two grounds
that are interconnected are also electrically different. Different
grounds even when interconnected are electrically different.

Returning to this thread's point. Earth ground has no relevance to
the ground for a static electric discharge circuit. An electric
circuit from leg, through arm, through computer chassis, through
table, and to bottom of shoe. Earth ground exists where in that
circuit? No where. Earth ground does nothing for semiconductor
static protection. One here has assumed motherboard ground is same as
earth ground.
Hardly.

Without or without earth ground connected to a computer, a static
electric discharge from finger to semiconductor will damage (or over
stress) that semiconductor. (Over stress is another relevant
concept.) Where is protection provided by earth ground? Non-
existent. Earth ground or safety ground (also called equipment ground
because it is different from earth ground) do nothing for static
electric protection.
Click to expand...

We don't want no floating grounds with ESD.
 
w_tom said:
If electrically correct, then a good place to ground a lightning rod
is to a computer chassis. Since ground inside a TV is same as ground
beneath your feet, then go ahead. Touch that TV ground. Pain from an
electrical shock demonstrates why two grounds are completely
different; why one ground is called a floating ground and not called
earth ground,

Motherboard ground is difference from wall receptacle safety ground;
is different from breaker box ground; is different from earth ground;
is different from telephone wiring ground; is different from chassis
ground; is different from any ground created by water pipes.

No grounding of electrical devices may be performed by water pipes.
Doing so can even threaten human life in a bathroom. Any ground
connection to water pipes only removes electricity from those pipes.
This requirement is a major safety code change. Grandfathering is the
only reason some safety grounds to water pipes can exist. And again,
a ground also called water pipes is electrically different from all
those other grounds.

Knowledge of basic electricity means that electricity is always
different at two ends of a wire. Sometimes that difference is so
minor as to be considered same. But two ground connected at two ends
of a wire are electrically different. Why do many electronic devices
contain separate analog and digital grounds? But again, two grounds
that are interconnected are also electrically different. Different
grounds even when interconnected are electrically different.

Returning to this thread's point. Earth ground has no relevance to
the ground for a static electric discharge circuit. An electric
circuit from leg, through arm, through computer chassis, through
table, and to bottom of shoe. Earth ground exists where in that
circuit? No where. Earth ground does nothing for semiconductor
static protection. One here has assumed motherboard ground is same as
earth ground.
Hardly.

Without or without earth ground connected to a computer, a static
electric discharge from finger to semiconductor will damage (or over
stress) that semiconductor. (Over stress is another relevant
concept.) Where is protection provided by earth ground? Non-
existent. Earth ground or safety ground (also called equipment ground
because it is different from earth ground) do nothing for static
electric protection.
Click to expand...
This is why we put on a wrist grounding strap before
we touch the case or boards.
 
w_tom said:
If electrically correct, then a good place to ground a lightning rod
is to a computer chassis. Since ground inside a TV is same as ground
beneath your feet, then go ahead. Touch that TV ground. Pain from an
electrical shock demonstrates why two grounds are completely
different; why one ground is called a floating ground and not called
earth ground,
Click to expand...
You don't know what you are talking about. Floating grounds are not for
ESD.
Motherboard ground is difference from wall receptacle safety ground;
is different from breaker box ground; is different from earth ground;
is different from telephone wiring ground; is different from chassis
ground; is different from any ground created by water pipes.
Click to expand...

No it's not. Check it out. The neutral and the earth ground are tied
together in the electrical panel.
No grounding of electrical devices may be performed by water pipes.
Doing so can even threaten human life in a bathroom. Any ground
connection to water pipes only removes electricity from those pipes.
This requirement is a major safety code change. Grandfathering is the
only reason some safety grounds to water pipes can exist. And again,
a ground also called water pipes is electrically different from all
those other grounds.
Click to expand...
The water pipe is the same as the ground pin on your electrical tool.
Water pipes usually are cabled to earth ground with a ground rod driven
into the ground to avoid false grounds. The same place your electrical
panel is grounded.
 
w_tom said:
If electrically correct, then a good place to ground a lightning rod
is to a computer chassis.
1+1=5


No grounding of electrical devices may be performed by water pipes.
Doing so can even threaten human life in a bathroom. Any ground
connection to water pipes only removes electricity from those pipes.
This requirement is a major safety code change. Grandfathering is the
only reason some safety grounds to water pipes can exist.
Click to expand...

Complete nonsense. In the US, the National Electrical Code has required
water pipes (at least 10 ft. metal in ground) to be a power system
grounding electrode since 1777. (Connections must now be made within 5
ft. of the entrance of the pipe to the building.) “Removes electricity
from those pipes” is technical illiteracy.
Returning to this thread's point. Earth ground has no relevance to
the ground for a static electric discharge circuit. An electric
circuit from leg, through arm, through computer chassis, through
table, and to bottom of shoe. Earth ground exists where in that
circuit? No where. Earth ground does nothing for semiconductor
static protection. One here has assumed motherboard ground is same as
earth ground.
Click to expand...

Static electricity does not involve a normal "circuit". Excess electrons
are accumulated (or lost) from the charged object. When connected to
another object, electrons may flow only to the 2nd object spreading the
excess (shortage) of electrons over both objects. When static is
discharged I agree it is better if the 2nd object is 'grounded'. When
servicing that isn't a particular factor - equal voltage is.
 
When
servicing that isn't a particular factor - equal voltage is.
Click to expand...

Indeed - that's why I developed the habit of keeping in contact with the
case; also all tools, bags etc. touched to case before use.
 
bud-- said:
Complete nonsense. In the US, the National Electrical Code has required
water pipes (at least 10 ft. metal in ground) to be a power system
grounding electrode since 1777. (Connections must now be made within 5
ft. of the entrance of the pipe to the building.) “Removes electricity
from those pipes” is technical illiteracy.
Click to expand...
Actually now with all plumbing being PVC, CPVC, molybutylene,
polybutylene, ABS, PE, PEX or plastic, grounding water pipes is now
invalid or a useless practice.
 
We don't want no floating grounds with ESD.
Click to expand...

So which is it? Are all grounds are same or electrically
different? Blattus said all grounds are same:
Ground is ground is ground. Static electricity is no
different that any other electricity.
Click to expand...

Now Blattus says otherwise? He also claimed earth ground provides
ESD protection in direct contradiction to what the motherboard
manufacturer recommends. Blattus did not understand electrical
differences between grounds. Meanwhile earth ground does nothing for
ESD protection.

Do not leave a computer connected to wall receptacle when
installing or removing components - as the motherboard manual says.
As in the OP:
It says to unplug the power supply when you remove or
install hardware components.
Click to expand...

Only ground that matters in ESD protection is ground beneath your
shoes. Connection to that ground is via items otherwise considered non-
conductive such as the table and an anti-static wrist strap.
Provided was a circuit - the reason 'why' that motherboard
manufacturer is correct. Blattus Slafaly would contradict the
manufacturer? Having looked at his reasons 'why', he did not
understand that grounds are electrically different. Now his is
backtracking.

Expanding on important safety considerations: a wrist strap is not
conductive to typical computer electricity. But strap is conductive
to static electric discharges. Electrical characteristics essential so
that a wrist strap does not kill a human who is accidentally
electrically shocked. Do not use wire as anti-static protection.

Other solutions to ESD protection include humidity and static
conductive plastics on table top and on the floor beneath shoes. Work
with aerospace hardware to appreciate why these solutions are required
religiously. Each solution is about discharging static electricity or
preventing the formation of a static charge.

Naively posted:
If you just rely on the bench ground where the computer
case is sitting (which is also connected to earth ground
by it's outlet power) you may have insufficient contact and
charge your case to 3 to 10 kv or more by touching it.
Click to expand...

Incorrect. How does a chassis charge to 10K volts when it is in
contact with conductive materials? Blattus Slafaly does not grasp
what is and is not conductive. If a chassis is not electrically
isolated, then chassis does not charge to 10 Kv. Even table can mean
a chassis is not electrically isolated. (Meanwhile, humans create up
to 18k or 20K volts which is known when one learns the 'whys' of ESD
protection.)

Discharging to any semiconductor, especially with case connected to
earth ground, means static electric currents still flow destructively
through that semiconductor. Where is protection? Does not exist for
the same reason that a power cord connection also does not provide ESD
protection. Connect a wrist strap to computer chassis so that the
body is discharged through a chassis to bottom of shoes. Wrist strap
is to discharge a body so that body, computer, and floor are at same
voltage potential.

No electrical device must be grounded to water pipes. Long ago,
electrical items were grounded to water pipes; to dump electricity
into those pipes. That connection is no longer acceptable. Every
connection to water pipes (including the one from breaker box to where
those pipes leave the building) is only to remove electricity from
pipes - to reduce pipe voltages to same as breaker box. The
electrical connection permitted (and required) to water pipes is from
breaker box - to remove hazardous voltages from those pipes which is
also called 'removing electricity'. That is a major code change that
also says computer chassis must not be connected to water pipes. Any
computer connected to water pipes can become a human safety hazard.
 
Indeed - that's why I developed the habit of keeping in contact with
the case; also all tools, bags etc. touched to case before use.
Click to expand...

A wrist strap is to discharge the body. Connect charges to ground
beneath shoes. Accomplish same by touching the chassis performing
work. If without a wrist strap, a repairman must be careful to not
move his feet; not create more charges.

Above are techniques to discharge a body. Another technique is
called the Eprom handshake. Before one technician hands a
semiconductor to another, both perform a handshake by touching their
'back of hands'. Both technicians become same potential so that when
a semiconductor is handed off, no ESD currents pass through that
semiconductor. A symptom of improper transfer is a changed data bit
in that Eprom.
 
w_tom said:
No electrical device must be grounded to water pipes. Long ago,
electrical items were grounded to water pipes; to dump electricity
into those pipes. That connection is no longer acceptable. Every
connection to water pipes (including the one from breaker box to where
those pipes leave the building) is only to remove electricity from
pipes - to reduce pipe voltages to same as breaker box. The
electrical connection permitted (and required) to water pipes is from
breaker box - to remove hazardous voltages from those pipes which is
also called 'removing electricity'.
Click to expand...
..
Repeating:
“Complete nonsense. In the US, the National Electrical Code has required
water pipes (at least 10 ft. metal in ground) to be a power system
grounding electrode since 1777.”
w_ has been corrected numerous times by electricians and others. The
NEC is absolutely clear. It takes willful stupidity to keep repeating
this drivel.

“Dump electricity” and “removing electricity” are technical illiteracy.

A large majority of buildings in the US are likely still supplied by
metal water pipe.
 
bud-- said:
.
Repeating:
“Complete nonsense. In the US, the National Electrical Code has required
water pipes (at least 10 ft. metal in ground) to be a power system
grounding electrode since 1777.”
w_ has been corrected numerous times by electricians and others. The
NEC is absolutely clear. It takes willful stupidity to keep repeating
this drivel.

“Dump electricity” and “removing electricity” are technical illiteracy.

A large majority of buildings in the US are likely still supplied by
metal water pipe.
Click to expand...
And can everybody keep it a secret for w_tom, that all water with
some minerals in it, like salt etc, perfectly conducts static
electricity, and that the water in a plastic pipe will do fine for
static? We are talking about microamps, and even water with several
kiloohms resistance will take care of those itty bitty currents.
Even a slightly damp wooden floor will protect you from static buildup.
Its just not save for isolation failures in equipment, but that
is another subject.
 
And can everybody keep it a secret for w_tom, that all water with
some minerals in it, like salt etc, perfectly conducts static
electricity, and that the water in a plastic pipe will do fine for
static?
Click to expand...

How is that water pipe in a circuit from arm, through semiconductor,
down to floor, to charges beneath feet? It is not. Earthing does not
provide static electric protection. Earthing a computer chassis does
not discharge a human body. Metal pipes, water in plastic pipes, and
earth ground is irrelevant to ESD protection.

Why discss what is irrelevant to the OP's question? Why discuss
what is irrelevant to what the motherboard manufacturer says? Water in
pipes is irrelevant here. Makes absolutely no difference whether water
is a best conductor or worst conductor. That water is not in a
circuit to discharge static electricity.

Motherboard manufacturer wants power cord disconnected from a
computer before performing service. Connecting that computer to earth
ground via receptacle's safety ground or via water in a pipe does
nothing for motherboard ESD protection. Motherboard manual is blunt
and correct. Disconnect power cord before doing any component
installation or removal - as defined by reasons posted here.
Essential to ESD protection is an anti-static wrist strap connected to
chassis - or some equivalent connection.

Water conductivity implies Sjouke did not read or grasp what was
posted and what is being discussed. Water in air is relevant -
humidity. Higher humidity is one solution to protecting a motherboard
from ESD damage. Water inside a pipe is obviously completely
irrelevant. See Paul's post (of 3 Feb) to appreciate who does
understand ESD protection.
 
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