Numerous responses that don't even demonstrate knowledge of
what a surge protector does. Lets take that Isobar as
example. One even made some silly claim that torroids provide
the protection. Isobar does same thing that most every
plug-in protector and UPS does. One reason why you know this
is in the specifications. They are all rated in joules
because they all have same protection circuit.
Look. Lightning has traveled through miles of air to obtain
earth ground, destructively, via your computer. Are those
silly one inch components going to stop what miles of
non-conductive air did not? Of course not. But to work, that
Isobar must stop, block, or absorb the transient. How does
the Isobar stop miles of lightning? It does not even claim
to perform that magic.
Ben Franklin demonstrated the concept. Lightning sought
earth ground via the church steeple. Franklin simply provided
an electrically shorter path to earth. He shunted, diverted,
connected lightning to earth ground in 1752. Before WWII,
this was well proven in virtually every town - by example.
Surge protection is about earthing before transient can enter
the building. It was that well understood way back then.
To sell ineffective, overpriced protectors, they simply
avoid all earthing discussion - to keep you ignorant and to
promote urban myth purveyors. To claim surge protector
status, they provide a unit that protects from a type of surge
that does not typically exist. Then they leave the naive to
make this mythical word association and assumption - "surge
protector is surge protection".
Back to reality. A surge protector is only effective when
it shunts (connects) to surge protection. Those are separate
components of a surge protection 'system'. Some surge
protection 'systems' don't even require a surge protector.
But the one component necessary in all surge protection
'systems' is earth ground. No earth ground means no effective
protection. Not one of your replies ever even mentioned the
fundamental point made even in 1930s research papers. Earth
ground.
A surge protector is only as effective as its earth ground.
Is your Isobar worn out? Doubt it. Destructive transients
occur typically once every eight years. Furthermore, without
a short (less than 10 foot) connection to earth ground, then
Isobar may have never seen that potentially destructive
transient. Transient passed right past without being observed
by protector. Again, there are many types of transients.
Computers already have effective protection internally. If
the $0.10 components inside an Isobar were so effective, then
they would already be inside the computer.
How effective is that internal protection? Well, lets look
at the output of a UPS that has a simulated sine wave output.
Under no load, the 120 volts is two 200 volt square waves with
a 280 volt spike between those square waves. This is a
simulated sine wave that provides the equivalent of 120 VAC
into computer. Will simulated sine wave damage a computer?
Of course not. Computer power supplies are so resilient that
even the much dirtier power from a UPS does not adversely
affect a computer. However do not run some small electric
motors on this UPS. Small motors may be damaged by a voltage
output that cannot harm a computer.
Any protector adjacent to the computer, if effective, is
already inside that computer. But this internal protection
assumes you have installed 'whole house' protector - to earth
any destructive incoming transient. If incoming transient is
not earthed where utility wires enter building, then that
transient can overwhelm a computer's existing internal
protection.
'Whole house' protectors are so effective and so inexpensive
that your telco provides one inside your premise interface.
Yes, your phone wires already have effective protector
installed for 'free'. But the source of most destructive type
of surges (those that the Isobar does not even claim to
protect from) is via wires highest on the pole; wires that
enter the building without a 'whole house' protector .... AC
electric.
Effective AC electric protection costs about $1 per
protected appliance. How much did you spend for that Isobar
to only protect one appliance? $50. $70. That would be 50
or 70 times more for a protector that does not even claim to
provide the necessary protection. Does not even claim to
protect from a typically destructive type of transient. Get
specifications if you doubt this post. Post the common mode
and differential mode protection - or did they forget to
provide that information? Remember, they also forgot to
discuss earth ground.
This thread is chock full of urban myths. Learn some basic
information. Learn about effective protection that costs so
much less. Suggest you go to another previous discussion to
first learn what surge protection really is. This posted not
from what I have heard. This post from having designed this
stuff over many decades and having learned from IEEE research
papers. "RJ-11 line protection?" on 31 Dec 2003 in
pdx.computing, or
http://tinyurl.com/2hl53 and
"Opinions on Surge Protectors?" on 7 Jul 2003 in the
newsgroup alt.certification.a-plus or
http://tinyurl.com/l3m9
Bottom line - never forget this one sentence as you read
those discussions and what everyone else posts: a surge
protector is only as effective as its earth ground. Any
post that ignores this important point - earth ground - may
simply be promoting more urban myths. Note how many posters
only reported what they had heard rather than having first
learned basic circuit theory. No earth ground means no
effective protection.