Why is PC chasis put on voltage when earth/ground wire is mi

[Shaun]

"Hal" wrote in message
news:w8udnTz0t4vFSU3QnZ2dnUVZ8u6dnZ2d@giganews.com...

Knip----

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.
You need an EMI expert to answer this question. But I am shure that if there

are ways, they will be (much) more costly then the presently choosen
solution. So the second question is: "Are most customers willing to pay
extra for something, almost nobody (except you) is intersted in."

Hal


SkyTard Masturbating, You are such a fucking idiot!!!

The people that posted did answer your questions, you just to stupid to
realize it.



There are four ways that you can get voltage and current on the chassis.

1. The input filter capacitors on both and Hot and Neutral lines coming in
connect to chassis ground. This is so that capacitors remove most of the
electrical noise that is entering the PSU.

2. Leakage current caused by parasitic capacitance. Any conductor or
component inside the power supply will have a very small amount of
capacitance to the chassis, case of the power supply. The capacitance
causes a small amount of current to flow through the chassis to ground.

3. Induction. There are coils and transformers and wires all carrying
current, when there is current there is a magnetic field. Some of the field
is outside the coil or transformer and it will induce a current in the
chassis.

4. A major electrical fault where a bare part of a wire touches the power
supply case or a component comes partially loose and touches the case. This
will usually result in popping a fuse or breaker, which is by design. This
is what the ground wire is mostly for. You don't want 120 or 240 volts on
the chassis. In both of these cases the power supply should not be working
anymore either.


Shaun

 

[Shaun]

"Shaun" wrote in message news:N%TBp.13758$ar1.1707@newsfe08.iad...



"Hal" wrote in message
news:w8udnTz0t4vFSU3QnZ2dnUVZ8u6dnZ2d@giganews.com...

Knip----

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.
You need an EMI expert to answer this question. But I am shure that if there

are ways, they will be (much) more costly then the presently choosen
solution. So the second question is: "Are most customers willing to pay
extra for something, almost nobody (except you) is intersted in."

Hal


SkyTard Masturbating, You are such a fucking idiot!!!

The people that posted did answer your questions, you just to stupid to
realize it.



There are four ways that you can get voltage and current on the chassis.

1. The input filter capacitors on both and Hot and Neutral lines coming in
connect to chassis ground. This is so that capacitors remove most of the
electrical noise that is entering the PSU.

2. Leakage current caused by parasitic capacitance. Any conductor or
component inside the power supply will have a very small amount of
capacitance to the chassis, case of the power supply. The capacitance
causes a small amount of current to flow through the chassis to ground.

3. Induction. There are coils and transformers and wires all carrying
current, when there is current there is a magnetic field. Some of the field
is outside the coil or transformer and it will induce a current in the
chassis.

4. A major electrical fault where a bare part of a wire touches the power
supply case or a component comes partially loose and touches the case, or an
electronic component shorts out or fails. This
will usually result in popping a fuse or breaker, which is by design. This
is what the ground wire is mostly for. You don't want 120 or 240 volts on
the chassis. In these cases the power supply should not be working
anymore either.

The ground wire is there for your safety. I a major fault occurs inside the
PSU, it will usually trip a fuse or breaker to protect you from electric
shock. To get an electric shock you have to touch something live and
something grounded at the same time. The design of electrical equipment
follows UL specifications and it is designed to reduce electrical shocks
from equipment.

If you aren't using a ground to plug in you PC and you touch the case and
something grounded, you'll probably be ok and won't even notice it, but if
there is a component fault inside the power supply then you could get a
shock. If a major fault occurs in the power supply and the fuse / breaker
doesn't trip for some reason and you touch it and something ground you will
get a major shock. If you are in very poor health and using an ungrounded
device and a connection was made to you on or near a cut or incision and
another part of you touched ground, it can kill you.


Shaun