Whole house surge suppressors

[w_tom]

And again we have this misconception that a 'service entrance' and a
'point of use' protectors are protection. Again, protectors and
protection are two different components in a protection 'system'.
Again, protection is that single point earth ground. Protectors are
only electrical switches or connections to that single point ground.
A protector without that single point earth ground is doing nothing
effective.

The CATV line is as easy to protect as all other incoming utility
wires. It must first make a connection to single point earth ground -
the protection - before entering the building. Newly revitalized
cable companies are now teaching their employees this 60+ year old
technology. Technology that long understood and that repeatedly
proven. And yet still, here in the 21st Century, we still have people
'assuming' a protector is protection. A protector is only as
effective as its earth ground. How does the incoming cable get
protected? Throw away the protector and connect that incoming cable
direct - hardwired - to single point earth ground. No earth ground
means no effective protection.

Why might the TV be damaged on its cable connection? If cable was
properly earthed, then incoming transient is on some other utility.
One typical incoming source is the AC electric (especially if
appliance is connected to an adjacent plug-in protector). Incoming on
AC electric, through TV, and outgoing to earth ground via cable.
First everything in an electrical path from cloud to ground conducts
the transient. Only then does one device in that path fail - often a
component on TV's cable connection. Many then assume the surge came
in on cable when, in reality, surge was incoming on AC electric and
outgoing on cable connection.

 

[Charles Perry]

[email protected] (Bob S.) wrote in message

Do you have surge suppressors that provide surge reference equalization?
What that means is a surge suppressor with power and cable protection in the
same box. Even if the grounds for both electric and cable service are
grounded at the same point, it is still possible to end up with an induced
potential between them at your television. The suppressor with both power
and cable protection will clamp this potential at a safe level.

Charles Perry P.E.

 

[SQLit]

Can you chain MOV's to defeat second spikes?

That is basicly what the zones of protection do. The first takes it down as
much as it can then the next does its job and hopefully that takes it to a
level that the point of use can handle.

If you have this much time and money, why not put a lightning rod on the
roof?

Rods on the roof only help protect the building. My thrust is to protect my
sensitive electronics. Not the structure.

 

[chris]

Hi

If the structure gets hit by lightning and catches fire, Electronics are the
least of your worries.

Chris

 

[A]

More interesting for A+ students is which class of fire extinguisher is used
specifically on electrics. I got this question a few weeks ago in the Core
exam. I've also had two friends over the years who have had direct hits by
lightening. The damage is incredible! Alan.

This is a most informative article, and it echoes what w_tom says:
http://www.ecmweb.com/mag/electric_hit_grounding_home/

So when I call an arbitrary electrician to ask for a grounding survey,
how do I know he's telling me the truth?

Do I have to pay hundreds or thousands of dollars to purchase a ground
tester?

This is for a single family home that I have lived in for about 7 years,
and will probably continue to live in for about 7 more years.


Since I'm having electrical work done, I would also like something like
this: http://scientificsonline.com/product.asp_Q_pn_E_3108400 installed
at my breaker box; it would be nice if it could break down it's info by
each breaker; and it would also be nice if it could tell me how much
current is flowing through my ground connection.


Here are random URLs of info:
http://groups.google.com/groups?hl=...s_miny=2002&as_maxd=25&as_maxm=8&as_maxy=2003

http://amasci.com/amateur/whygnd.html

http://groups.google.com/groups?hl=...=3&prev=/groups?q=ground+neutral+hot&ie=UTF-8
%26hl%3Den%26btnG%3DGoogle%2BSearchhttp://groups.google.com/groups?hl=en&lr=&ie=UTF-8&threadm=8gdgt7%24esp%241%40news.efn.org&rnum=1&prev=/groups%3Fq%3Dground%2Bneutral%2Bhot%26ie%3DUTF-8%26hl%3Den%26btnG%3DGoogle%2BSearchhttp://groups.google.com/groups?hl=en&lr=&ie=UTF-8&threadm=rLpu0fAF53T6EwcJ%40lineone.net&rnum=8&prev=/groups%3Fq%3Dground%2Bneutral%2Bhot%26ie%3DUTF-8%26hl%3Den%26btnG%3DGoogle%2BSearchhttp://groups.google.com/groups?hl=en&lr=&ie=UTF-8&threadm=w5nsc.34575%24zw.8611%40attbi_s01&rnum=20&prev=/groups%3Fq%3Dground%2Bneutral%2Bhot%26hl%3Den%26lr%3D%26ie%3DUTF-8%26start%3D10%26sa%3DNhttp://groups.google.com/groups?hl=en&lr=&ie=UTF-8&threadm=U%25046.32481%24bw.2026859%40news.flash.net&rnum=26&prev=/groups%3Fq%3Dground%2Bneutral%2Bhot%26hl%3Den%26lr%3D%26ie%3DUTF-8%26start%3D20%26sa%3DN




Here is a summary of models I have found, and some anecdotes from
Usenet:

MODEL: Panamax Primax
RESELLER: SmartHome.com http://www.smarthome.com/4839.html
JOULES: 2700
AMPS: 60,000
CIRCUIT TYPE: 120/240 1 Phase, 50/60 Hz
RESPONSE TIME: 8x20 microseconds
PRICE: $119.99
WARRANTY: the manufacturer provides a 3-year Connected Major Appliance
Protection Policy up to $10,000 for the repair or replacement of major
household appliances (refrigerator, freezer, oven, range, washer, dryer,
ceiling fan or dishwasher) and a 5-year product warranty.
URLS:
- Press Release:
http://groups.google.com/groups?q=p...01bd5cec$605a2680$77003dce@oemcomputer&rnum=3

- Negative Experiences:
http://groups.google.com/groups?q=p...on=us&[email protected]&rnum=4

- More Negative Experiences:
http://groups.google.com/groups?hl=...=UTF-8&edition=us&q=panamax+surge&btnG=Search

MODEL: Leviton 51120-1
RESELLER: SmartHome.com http://www.smarthome.com/4860.html
JOULES: 950
AMPS: 50,000
CIRCUIT TYPE:
RESPONSE TIME: "Instantaneous"
PRICE: $189.99
WARRANTY:
URLS:
- Positive Comment:
http://groups.google.com/groups?hl=...lm=tia8dac62nojbf%40corp.supernews.com&rnum=4

- Negative Comment:
http://groups.google.com/groups?q=l...n=us&[email protected]&rnum=3

- Positive Comment:
http://groups.google.com/groups?q=5...e=UTF-8&[email protected]&rnum=2

MODEL: Panamax gpp8005
RESELLER: PowerSystemsDIRECT
http://www.powersystemsdirect.com/P...ector_Whole_House_Surge_Primax_gpp8005_55.php

JOULES: 2,700
AMPS: 60,000
CIRCUIT TYPE: 120/240 1 Phase 50/60Hz
RESPONSE TIME:
PRICE: $99.99
WARRANTY: Connected Equipment Policy Length 3 Years; Connected
Equipment Policy Amount $10,000; Lightning Protection Yes
URLS:
Model description:

MODEL: Intermatic IG1240RC
RESELLER: SmartHomeUSA.com
http://www.smarthomeusa.com/Shop/Lighting/Surge-Suppressors/Item/IG1240RC/

JOULES: 1,200
AMPS: 48,000
CIRCUIT TYPE: 120/240V 60Hz
RESPONSE TIME: Less than 5 nanoseconds
PRICE: $69.95
WARRANTY: $10,000 warrantee
URLS:
- Positive:
http://groups.google.com/groups?hl=...s&selm=7ukvpr%24dja%241%40news.mks.com&rnum=2

- Positive:
http://groups.google.com/groups?hl=...&ie=UTF-8&edition=us&q=intermatic&btnG=Search

- Positive:
http://groups.google.com/groups?q=i...tion=us&[email protected]&rnum=3

- Informational:
http://groups.google.com/groups?q=i...=us&[email protected]&rnum=2

MODEL: Intermatic PanelGuard IG1300-4T-2C, protects (?) phone-lines and
cable lines too
RESELLER:
JOULES:
AMPS: 48,000
CIRCUIT TYPE: 120/240 single (split) phase, 4 telephone lines, and 2
coax cable lines; ALL MODE PROTECTION (L1-N, L2-N, L1-G, L2-G, N-G,
L1-L2); 150 Volt MOVs (Metal Oxide Varistors) [AC Protection]; 350 Volt
Gas Tube [Telephone Protection]; 90 Volt Gas Tube [Coax Cable /
Satellite Protection]
RESPONSE TIME:
PRICE: IG1300-2T is $152.83 at
http://www.aplussupply.com/intermatic/pg5000/ig1240.htm
WARRANTY: $10,000, 5 year warranty
URLS:
- Non-negative:
http://groups.google.com/groups?hl=...s?q=IG-1300&ie=UTF-8&hl=en&btnG=Google+Search

- Positive:
http://groups.google.com/groups?hl=...s?q=IG-1300&ie=UTF-8&hl=en&btnG=Google+Search

MODEL: Ditek DTK-WH8 Whole House Kit
RESELLER: StayOnline
http://www.stayonline.com/panel_surge_protectors/3233.asp
JOULES: 1050
AMPS: 125,000
CIRCUIT TYPE: 120 / 240 Split Phase ; Suppressed Voltage Rating: 700V
(L-L), 400V (L-G, L-N, N-G)
RESPONSE TIME: Less than 5 nanosecond
PRICE: $149
WARRANTY:
URLS:

MODEL: PolyPhaser IS-PM120-SP
RESELLER: PolyPhaser.com
JOULES:
AMPS: 40,000
CIRCUIT TYPE: 120Vac, 1 Phase, 2 Wires & GND
RESPONSE TIME: ?? Turn-On Time: 25ns ??
PRICE:
WARRANTY:
URLS:
- Positive:
http://groups.google.com/groups?q=l...n=us&[email protected]&rnum=3

 

[John Popelish]

SQLit wrote:
(snip)

Rods on the roof only help protect the building. My thrust is to protect my
sensitive electronics. Not the structure.

Would you rather a hit follow the wiring running through the structure
(and jump through whatever was in the way as it hops between various
conductors and objects) as it finds its way to ground, or would you
rather that this current be directed through an intentional path?

I know which I would choose.

 

[Roy McCammon]

I picked up one at Home Depot. They only had GE, but I was in luck
because my service entrance box was GE. I just kept it on hand and when
I had an electrician out for another problem, I had him install it.

I don't know if it works, but I've convinced my wife to stop buying
the useless ones and I'm ahead on dollars.

 

[Charles Perry]

I picked up one at Home Depot. They only had GE, but I was in luck
because my service entrance box was GE. I just kept it on hand and when
I had an electrician out for another problem, I had him install it.

I don't know if it works, but I've convinced my wife to stop buying
the useless ones and I'm ahead on dollars.

What "useless ones"? If you do not have a separate TVSS at your appliance
(whether computer or television) that includes plugs for power and
communications (cable and/or telephone) then you will likely experience
damage to an appliance some day.

Charles Perry P.E.

 

[Rich Grise]

More interesting for A+ students is which class of fire extinguisher is
used specifically on electrics.

It's a trick question. You can use a C, an AC, a BC, or an ABC. An
electrical fire is a type "C" fire.

I got this question a few weeks ago in the
Core exam. I've also had two friends over the years who have had direct
hits by lightening. The damage is incredible! Alan.

I was in an apartment that got hit once. Luckily, I had had the notion
to unplug the modem. ;-) The answering machine was a total loss, and
the TV had the weirdest malfunction I've ever seen - it wouldn't turn
off! I paid a tech $35 to diagnose it, and I replaced the transistor
myself. Down the hallway, at least one exit light had had the front
panel blown off, and the lamp was dangling by its wires. The manager
said there was about $7,000 worth of damage from the one strike.

 

[Roy McCammon]

What "useless ones"? If you do not have a separate TVSS at your appliance
(whether computer or television) that includes plugs for power and
communications (cable and/or telephone) then you will likely experience
damage to an appliance some day.

Charles Perry P.E.

I don't believe separate TVSS provide any significant protection.

Roy McCammon P.E.

 

[Charles Perry]

I don't believe separate TVSS provide any significant protection.

Roy McCammon P.E.

We have tons of test data proving that it is necessary to provide a surge
equilization TVSS at any equipment that is powered from the electrical
system and connected to one, or more, communication systems.

Read this:

http://www.eeel.nist.gov/817/817g/spd-anthology/files/Enlightening.pdf

Charles Perry P.E.

 

[w_tom]

The GE model seen previously is only sold in Lowes and is called
THQLSURGE if I remember correctly. It costs more than the Intermatic
IG1240RC sold in Home Depot and is undersized. That means it still
will work, but will have a significantly shorter life expectancy.
There are a few 'whole house' or breaker box protectors that are
undersized and still cost more money. Square D also makes an
undersized one. But Square D also makes a properly sized and
effective model as well. Benchmark for a minimally acceptable 'whole
house' protector is about 1000 joules and 50,000 amps. Same could be
accomplished by installing two GE THQLSURGE - both making a less than
10 foot connection to earth ground.

 

[w_tom]

Appliances already have effective internal protection. With a
properly installed 'whole house' protector and the so critical earth
ground, then any induced potential inside the building will remain
well below what appliances are designed to withstand. A 'whole house'
protector may not be perfect. But with it, residual transients inside
a building should remain at below what appliances must withstand;
below those ratings of appliance internal protection.

Anything that can be effective adjacent to the appliance is already
inside that appliance. One of the early requirements for such
internal protection was the CBEMA. Even Intel specifications for
power supplies require sufficient internal protection. Internal
protection that assumes the 'whole house' protector exists and that
all incoming utilities are properly earthed to the single point earth
ground.

 

[Dave Holford]

Reality check here....I don't care what surge protection you use, if
lightning hits your stuff its fried.

So how do radio stations, radar sites on mountains, etc. which take
multiple hits manage to survive?

Dave

 

[Charles Perry]

Appliances already have effective internal protection. With a
properly installed 'whole house' protector and the so critical earth
ground, then any induced potential inside the building will remain
well below what appliances are designed to withstand. A 'whole house'
protector may not be perfect. But with it, residual transients inside
a building should remain at below what appliances must withstand;
below those ratings of appliance internal protection.

Anything that can be effective adjacent to the appliance is already
inside that appliance. One of the early requirements for such
internal protection was the CBEMA. Even Intel specifications for
power supplies require sufficient internal protection. Internal
protection that assumes the 'whole house' protector exists and that
all incoming utilities are properly earthed to the single point earth
ground.

The problem is not with the power supply, it is with the communications
ports. Nine out of ten failed appliances that we examine have failures
associated with the communications ports. If you don't provide the proper
TVSS that ties the power and communications references together, then you
will damage equipment.

http://www.eeel.nist.gov/817/817g/spd-anthology/files/Enlightening.pdf

A very good paper that mentions this.

Charles Perry P.E.

 

[w_tom]

Yes communication ports are easily damaged where they are used beyond
what they were designed for. Two examples are RS-232 ports and
outside speakers to a stereo amp. However first one must ask where
was the incoming and outgoing path for that damage.

Does a surge enter on communication port, damage that port, then
stop? Of course not. First a complete circuit is established from
cloud to earth. After that circuit is conducting electricity through
everything in that circuit, only then does something fail. If that
circuit is incoming and outgoing via appliance - a condition where
1000+ volts means the 'whole house protector system was defective -
then the solution is not to supplement the protector. The solution is
to fix the 'whole house' protector and its so critically necessary
earth ground.

As noted previously, many communication ports, to communicate with
devices not adjacent to the computer, already have effective internal
protection. For example NIC (ethernet) port is typically good for in
excess of 1000 volts. That is effective protection that can be
overwhelmed if the necessary 'whole house' protector system is not
installed. Most critical component of that system? Single point
earth ground.

Do we fix the single point ground or do we install 'point of use'
protectors on every of well over 100 appliances inside the house?
Remember, GFCIs in kitchen and bathroom, furnace, electronic timer
switch, dishwasher, clock radio, portable phone, microwave, alarm
system - are but a few of the electronics that each need a $15 or $50
protector if the 'whole house' system is not properly installed.
Better and less expensive to fix the 'whole house' (secondary)
protection system.

Charles Perry cites a paper that is a 'must read' for anyone who
needs surge protection:
http://www.eeel.nist.gov/817/817g/spd-anthology/files/Enlightening.pdf
Same authors make same point in an applicaton note for builders and
other structural contractors - again must read:
http://www.pueblo.gsa.gov/cic_text/housing/surge/contractors.htm

In the Cozy Cabin example, simple principles of single point earth
ground are violated. Damage was made possible by human failure. The
Rambling Residence suffers from a similar failure. For example,
outside speakers are incoming wires that did not first connect to
single point ground before leaving the building. Where did that
transient enter or leave? The authors suspect induced electromagnetic
transient. However those wires easily could have been connected to a
direct surge by being buried, routed over conductive materials such as
concrete, or even in contact with another conductor - the tree. But
again, wires entered the building without first making contact to the
single point earth ground system. A blantant violation.

Other suspects could have contributed to the problem. Electrical
controls for the sprinkler system also complicate the installation of
a single point ground. Where or how did another structure - the
exterior pool - connect to building? Were building and pools
interconnected at a single point or did they too create ground loops?
Both pool and building should have been connected as if each were a
separate structure. If not, then the building could have ground loop
problems - no single point earth ground existed.

Earthing is the primary solution to surge protection which is also
why new homes should have Ufer or halo grounds. Grounding installed
bfore the foundation is even constructed. Purpose is to make earth
beneath equipotential - make the single point ground more effective.
Plug-in or 'point of use' protectors do not adaquately compensate for
a defective earthing system. Furthermore those plug-in protectors are
typically undersized and grossly overpriced - on the order of tens of
times more expensive per protected appliance.

That is the point of that nist.gov paper and so many other
industry professionals. Protectors are not the protection. Earthing
- the thing often forgotten because it is out of sight - is the most
important aspect of surge protection.

And we are only discussing secondary protection. What is the
primary protection? Examples of failures in a building's primary
protection system:
http://www.tvtower.com/fpl.html
Again, the less expensive and essential solution is earthing even in
the primary protector system.

 

[w_tom]

Communication ports are easily damaged if ports are used beyond their
design criteria. Two examples are RS-232 port to interconnect
buildings and stereos driving outside speakers. However, first one
must ask where was the incoming and outgoing path for that damage.
Does a surge enter on communication port, damage that port, then stop?
Of course not. First a complete circuit is established from cloud to
earth. After that circuit is conducting electricity through
everything in that circuit, only then does something fail. If that
circuit is incoming and outgoing via appliance - a condition where
1000+ volts means the 'whole house protector system was defective -
then the solution is not to supplement the protector. The solution is
to fix the 'whole house' protector and its so critically necessary
earth ground.

As noted previously, many communication ports, to communicate with
devices not adjacent to the computer, already have effective internal
protection. For example NIC (ethernet) port is typically good for in
excess of 1000 volts. That is effective protection that can be
overwhelmed if the necessary 'whole house' protector system is not
installed. Most critical component of that system? Single point
earth ground.

Do we fix the single point ground or do we install 'point of use'
protectors on every of well over 100 appliances inside the house?
Remember, GFCIs in kitchen and bathroom, furnace, electronic timer
switch, dishwasher, clock radio, portable phone, microwave, alarm
system - are but a few of the electronics that each need a $15 or $50
protector if the 'whole house' system is not properly installed.
Better and less expensive to fix the 'whole house' (secondary)
protection system.

Charles Perry cites a paper that is a 'must read' for anyone who
needs surge protection:
http://www.eeel.nist.gov/817/817g/spd-anthology/files/Enlightening.pdf
Same authors make same point in an applicaton note for builders and
other structural contractors - again must read:
http://www.pueblo.gsa.gov/cic_text/housing/surge/contractors.htm

In the Cozy Cabin example, simple principles of single point earth
ground are violated. Damage was made possible by human failure. The
Rambling Residence suffers from a similar failure. For example,
outside speakers are incoming wires that did not first connect to
single point ground before leaving the building. Where did that
transient enter or leave? The authors suspect induced electromagnetic
transient. However those wires easily could have been connected to a
direct surge by being buried, routed over conductive materials such as
concrete, or even in contact with another conductor - the tree. But
again, wires entered the building without first making contact to the
single point earth ground system. A blantant violation.

Other suspects could have contributed to the problem. Electrical
controls for the sprinkler system also complicate the installation of
a single point ground. Where or how did another structure - the
exterior pool - connect to building? Were building and pools
interconnected at a single point or did they too create ground loops?
Both pool and building should have been connected as if each were a
separate structure. If not, then the building could have ground loop
problems - no single point earth ground existed.

Earthing is the primary solution to surge protection which is also
why new homes should have Ufer or halo grounds. Grounding installed
bfore the foundation is even constructed. Purpose is to make earth
beneath equipotential - make the single point ground more effective.
Plug-in or 'point of use' protectors do not adaquately compensate for
a defective earthing system. Furthermore those plug-in protectors are
typically undersized and grossly overpriced - on the order of tens of
times more expensive per protected appliance.

That is the point of that nist.gov paper and so many other
industry professionals. Protectors are not the protection. Earthing
- the thing often forgotten because it is out of sight - is the most
important aspect of surge protection.

And we are only discussing secondary protection. What is the
primary protection? Examples of failures in a building's primary
protection system:
http://www.tvtower.com/fpl.html
Again, the less expensive and essential solution is earthing even in
the primary protector system.

 

[w_tom]

Communication ports are easily damaged if ports are used beyond their
design criteria. Two examples are RS-232 port to interconnect
buildings and stereos driving outside speakers. However, first one
must ask where was the incoming and outgoing path for that damage.
Does a surge enter on communication port, damage that port, then stop?
Of course not. First a complete circuit is established from cloud to
earth. After that circuit is conducting electricity through
everything in that circuit, only then does something fail. If that
circuit is incoming and outgoing via appliance - a condition where
1000+ volts means the 'whole house protector system was defective -
then the solution is not to supplement the protector. The solution is
to fix the 'whole house' protector and its so critically necessary
earth ground.

As noted previously, many communication ports, to communicate with
devices not adjacent to the computer, already have effective internal
protection. For example NIC (ethernet) port is typically good for in
excess of 1000 volts. That is effective protection that can be
overwhelmed if the necessary 'whole house' protector system is not
installed. Most critical component of that system? Single point
earth ground.

Do we fix the single point ground or do we install 'point of use'
protectors on every of well over 100 appliances inside the house?
Remember, GFCIs in kitchen and bathroom, furnace, electronic timer
switch, dishwasher, clock radio, portable phone, microwave, alarm
system - are but a few of the electronics that each need a $15 or $50
protector if the 'whole house' system is not properly installed.
Better and less expensive to fix the 'whole house' (secondary)
protection system.

Charles Perry cites a paper that is a 'must read' for anyone who
needs surge protection:
http://www.eeel.nist.gov/817/817g/spd-anthology/files/Enlightening.pdf
Same authors make same point in an applicaton note for builders and
other structural contractors - again must read:
http://www.pueblo.gsa.gov/cic_text/housing/surge/contractors.htm

In the Cozy Cabin example, simple principles of single point earth
ground are violated. Damage was made possible by human failure. The
Rambling Residence suffers from a similar failure. For example,
outside speakers are incoming wires that did not first connect to
single point ground before leaving the building. Where did that
transient enter or leave? The authors suspect induced electromagnetic
transient. However those wires easily could have been connected to a
direct surge by being buried, routed over conductive materials such as
concrete, or even in contact with another conductor - the tree. But
again, wires entered the building without first making contact to the
single point earth ground system. A blantant violation.

Other suspects could have contributed to the problem. Electrical
controls for the sprinkler system also complicate the installation of
a single point ground. Where or how did another structure - the
exterior pool - connect to building? Were building and pools
interconnected at a single point or did they too create ground loops?
Both pool and building should have been connected as if each were a
separate structure. If not, then the building could have ground loop
problems - no single point earth ground existed.

Earthing is the primary solution to surge protection which is also
why new homes should have Ufer or halo grounds. Grounding installed
bfore the foundation is even constructed. Purpose is to make earth
beneath equipotential - make the single point ground more effective.
Plug-in or 'point of use' protectors do not adaquately compensate for
a defective earthing system. Furthermore those plug-in protectors are
typically undersized and grossly overpriced - on the order of tens of
times more expensive per protected appliance.

That is the point of that nist.gov paper and so many other
industry professionals. Protectors are not the protection. Earthing
- the thing often forgotten because it is out of sight - is the most
important aspect of surge protection.

And we are only discussing secondary protection. What is the
primary protection? Examples of failures in a building's primary
protection system:
http://www.tvtower.com/fpl.html
Again, the less expensive and essential solution is earthing even in
the primary protector system.

 

[Charles Perry]

Yes communication ports are easily damaged where they are used beyond
what they were designed for. Two examples are RS-232 ports and
outside speakers to a stereo amp. However first one must ask where
was the incoming and outgoing path for that damage.

You missed part of the discussion of the paper I referenced. Even with
proper grounding, you can get a large induced voltage at the appliance.
Believe me. We have done the testing for NIST. A whole house surge
protector only protects for overvoltages on the power. It does NOT protect
for potential difference between power and communications. These potential
differences are the cause of many failures. Perhaps you should google a
NIST document called "Surges Happen".

Charles Perry P.E.

 

[w_tom]

Where is the major voltage difference between phone and AC electric if
both are properly earthed (a less than 10 foot connection) to same
earth ground? That is the point of that previously cited citation and
that application note for contractors. Not having all incoming
utilities earth 'less than 10 feet' to the single point earth ground
can cause voltage differences. If those voltage differences exist,
then the ineffective (improperly installed) 'whole house' systems with
single point earth ground is reason for failure. Notice how large
that failure must be to cause damage to many appliances. Voltage
differences of 600+ volts between phone line and AC electric just are
not possible if the 'whole house' earthing is properly installed.
That is even the point of your nist.gov citation. They cite bad
earthing in the Cozy Cabin and in the Rambling Residence. Bad
earthing resulted in that damage.

Anything added supplementary is up to the owner. But if the
original problem is not corrected, then (as I even demonstrated by
tracing the circuit and replacing blown semiconductors) the plug-in
protector can even contribute to damage of adjacent electronics.]

Solution is to fix the problem and not buy grossly overpriced cures
(plug-in protectors) to fix the original problem - the defective earth
ground and no 'whole house' protector.

I do appreciate what you recommend. I too once believed that stuff
originally in the 1970 GE Application Note (more like a book) for
MOVs. Since then I have learned that Polyphaser.com provides more
accurate information. Solve the problem where the problem exists -
single point earth ground AND short connections either by hardware or
through the 'whole house' protector.

I am reminded of an example in FL. They had lightning strike an
exterior bathroom wall twice. They had lightning rods installed.
Lightning ignored the lightning rods to strike bathroom wall a third
time. Why? Because lightning rods only connected to eight foot
ground rods in sand. Bathroom plumbing connected to more conductive
and deeper earth. Lightning damage because the earth ground was not
properly installed. Earthing is where primary and secondary
protection exists. Anything else (including series mode protectors
such as Brickwall, Zerosurge, and Surgex) are only supplementary AFTER
the primary and secondary protection systems are installed or
repaired.