How many smoke detectors - also not on surge protectors -
were damaged during the surge? Just because some things are
damaged and others are not does not justify a protector. One
must first review the details.
Some appliances will be in a path to earth ground. Others
may also be a path to earth ground, but be partially or
sufficiently protected by another (destroyed) appliance.
Furthermore, some appliances (even modems) may have better
internal protection. Ie. some modems use an off-hook relay
with a higher breakdown voltage. Numerous reasons why some
modems can fail whereas others survive. Even the length of
connecting wire changes the surge circuit (which is why an
earth ground connection must be less than 10 foot). I often
autopsy the modems and even up with some good modems by
replacing the failed transistor. IOW I trace the path of that
surge to learn why things fail. Repairing is not sufficient.
Unlike some others here, I am a trained and practicing
engineer who always wants to know 'why' failure happened.
Unlike those others here, I have no interest in posting 'proof
by insults'.
We know this from telephone exchanges, radio stations, and
even the original research performed on the Empire State
Building. Effective protection means shunting lightning to
earth ground before it can get near to appliances. This is
the less expensive as well as superior protection.
For example, in one set of networked computers, lightning
path to earth ground was discovered by literally replacing
each damaged semiconductor. They had three computers. Two
were on plug-in protectors. All computers were off.
Lightning struck the AC electric. It entered two computers
with power strip surge protectors. It exited both computers
via network interface chips. It entered a third computer via
the network interface chip and exited to earth ground via a
modem.
Notice what plug-in protectors did in this example.
Protectors actually completed the surge circuit. Protectors
shunted a surge into two networked computers. It does not
happen in every case. But depending on the circuit, a plug-in
protector can even contribute to adjacent computer damage.
If lightning passed through all three computers, then why
were ICs on motherboards also not damaged? Every computer
Integrated Circuit (IC) was exposed to the incoming transient
- just like every appliance inside a building is exposed. But
only those IC that had insufficient internal protection AND
that formed a complete circuit - both an incoming and outgoing
electrical path - were damaged.
Why was their TV and VCR not damaged by same surge? They
were not on power strip protectors. Devil is in the details.
Just because some things are and are not damaged is not
sufficient to say a surge protector works. One must analyze
at the component level - to literally trace the path of that
electrical current called a surge. Even wires become
electronic components in that analysis. If surge protector
was so effective, then what protected smoke detectors
dishwasher/ Both were not on protectors and not damaged. Why
did they not fail?
Many call lightning capricious. I don't. Lightning is
obviously simple once basic principles are understood.
Fundamental is earth ground. Lightning seeks earth ground.
Some appliances will be damaged when part of a path to earth.
Other adjacent appliances will not, in part, because they also
have better internal protection. Effective protection always
means the transient must be earthed before it can enter a
building. Follow the transient path to first appreciate how
and why protection works.
A telco wire would already have protection provided free.
However if still using the old 'carbons' then either your NID
should be upgraded or the carbons replaced. The old and long
obsoleted protection is:
http://thekramers.net/tmp/phonething.jpg
http://www.inwap.com/inwap/chez/Phoneline.jpg
Newer 'whole house' phone line protectors are:
http://www.alarmsuperstore.com/bw/bw connectors.htm
http://www.bass-home.com/gotoproduct.cfm?item=91598
Newer protectors are semiconductor based. IOW upon failure,
they typically short circuit. Unlike older technology
protectors (ie neon bulbs or the carbons), semiconductor
protectors announce their failure by cutting off phone
service. Also have lower capacitance meaning that they will
not compromise DSL and other newer services.
Second, a wire from phone line protector must be to same
earth ground used by AC electric and cable. Earthing wire
must meet the short, direct, and independent criteria posted
earlier.
Therein lies the protection on phone lines. But wires most
often struck are wires highest on pole. The most common
source of modem damage is AC electric. Even a wall wart power
supply for a modem will not stop or block this transient.
Furthermore, one AC electric wire makes a direct connection to
modems IC - internal or external modem. Incoming on AC
electric. Outgoing on phone line to earth ground. A typical
circuit that causes modem damage.
Again, incoming AC electric must also earth a surge before
it can enter the building. Most residential buildings do not
have this 'whole house' protector. Required for modem
protection is a 'whole house' protector on AC electric that
connected less than 10 feet to the same earth ground also used
by the telco NID box (telco provided surge protector).
