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w_tom w_tom is offline
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Default Surge / Ground / Lightning

On May 7, 8:07 am, wrote:
According to W_, surge protection is impossible unless there is
a direct and short connection to earth ground. Does the PC
power supply come with a built-in earth ground?


Again trader reads only what he wants to see. Surge protection
without that short connection to earth ground is *ineffective*.
trader, who understands propaganda in the Rush Limbaugh tradition,
changes the message - uses the word 'impossible'. Misrepresenting
reality is trader.

PC power supply has no built-in earth ground. How do others know?
They learned before knowing. For example, they read both front page
EE Times articles entitled “Protecting Electrical Devices from
Lightning Transients". trader did not. Those electrical concepts
were too complex. trader knows rather than first learn technology.

Had trader learned facts before posting, he would have read what
IEEE Standards also said (and is posted elsewhere). Defined by the
IEEE is effective protection - with numbers:
Still, a 99.5% protection level will reduce the incidence of direct
strokes from one stroke per 30 years ... to one stroke per
6000 years ...


What do 'whole house' protectors use? Enough MOVs so that protector
is sufficiently sized. So that direct lightning strikes does not
destroy the protector.

What do MOVs need to provide effective connection? That short (ie '
less than 10 foot') connection to earth.

What provides surge protection? Earth ground - where surge energy
is harmlessly dissipated.

What does the effective MOV do? Connects to earth so that surge
energy gets dissipated harmlessly rather than destructively inside the
building.

What must those MOVs inside appliances do (and why did Apple stop
using them after Apple II)? Those MOVs must somehow stop or absorb a
surge that even three miles of sky could not stop. So few joules will
somehow absorb all that energy. Such little devices will block what a
sky could not?

What happens when MOVs are too close to appliances and too far from
earth ground? Page 42 Figure 8 from another IEEE citation - surge
earthed 8000 volts destructively through the adjacent TV.

Provides were numerous professional citations that say this. Where
does trader even post technical numbers? He does not. trader is like
most who recommend plug-in protectors. They need not first learn
facts. They know. Their proof is by using insults – just like Rush
Limbaugh.

A protector is only as effective as its earth ground.