I've read a good deal about the above. Ideally, the grounds for various
(telephone, cable, power) electrical utilities should all be common; and
the service entries for those sundry services should be located within
15' of each other.

If I ever build a new house, I will take that into account.

However, it's not practical at this time to realize the ideal. What I
have currently is as follows:

The phone drop (two lines) comes in on one side of the house and is
grounded to the water supply line which comes in the front of the house
(about of 20' of wire clamped to the pipe where it comes through the
foundation into the unfinished basement).

The power drop (100 amp 220v single-phase) enters at the back of the
house, about 30' diagonally from the phone service. A ground wire
snakes from the panel (inside a utility porch) around a couple of
corners and through the floor to a ground post of unknown length/depth
in the crawl space beneath the adjacent kitchen...approximately 20 feet
of wire with at least two 90 degree bends.

The cable drop is around 15' feet from the power service entrance, and
grounded to an adjacent outside faucet a couple of feet away (all
plumbing in the house is copper).

Over the years, we've had a good deal of surge and lightning related
damage to devices in the house...most recently a DSL modem.

Would I derive any advantage by driving a new ground post outside,
adjacent to the power drop and to run all the various service grounds to
it (around 15' for cable, 25' or so for phone)?

Alternatively, I could move the telephone ground wire to the existing
power drop ground post (probably using the same 20' wire), and also
extend cable ground to this point. That would give me a 'star'
configuration with all utilities having around 20'-30' of wire from each
drop to ground.

Moving the phone service drop at this time (the ideal) is not practical.

jak

In article ,
jakdedert wrote:
The phone drop (two lines) comes in on one side of the house and is
grounded to the water supply line which comes in the front of the house
(about of 20' of wire clamped to the pipe where it comes through the
foundation into the unfinished basement).

Could anyone explain why a US telephone cable needs a local ground? Aren't
they balanced?

The UK system only used a local ground for shared local lines which went
out years ago.

--
*Work like you don't need the money. Love like you've never been hurt.

Dave Plowman London SW
To e-mail, change noise into sound.

System is balanced and isolated in US too. The ground is just for surge / lightning protection.

Eric Law

"Dave Plowman (News)" wrote in message ...
In article ,
jakdedert wrote:
The phone drop (two lines) comes in on one side of the house and is
grounded to the water supply line which comes in the front of the house
(about of 20' of wire clamped to the pipe where it comes through the
foundation into the unfinished basement).

Could anyone explain why a US telephone cable needs a local ground? Aren't
they balanced?

The UK system only used a local ground for shared local lines which went
out years ago.

--
*Work like you don't need the money. Love like you've never been hurt.

Dave Plowman London SW
To e-mail, change noise into sound.

It is used for lightning protection.. Believe me you really need if you
happen to live in Florida.

- Mike

"Dave Plowman (News)" wrote in message
...
In article ,
jakdedert wrote:
The phone drop (two lines) comes in on one side of the house and is
grounded to the water supply line which comes in the front of the house
(about of 20' of wire clamped to the pipe where it comes through the
foundation into the unfinished basement).

Could anyone explain why a US telephone cable needs a local ground? Aren't
they balanced?

The UK system only used a local ground for shared local lines which went
out years ago.

--
*Work like you don't need the money. Love like you've never been hurt.

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Eric Law wrote:
System is balanced and isolated in US too. The ground is just for surge
/ lightning protection.

Right. Few telephone cables in the UK are overground, so that explains it.
The surge arrestor here is just wired between the incoming pair.

--
*Time is fun when you're having flies... Kermit

Dave Plowman London SW
To e-mail, change noise into sound.

hmm.. I can't say I know of many overground telephone wires in my area,
except in older houses that have overhead power service, they used to string
the telephone wire under the power wire, but the main phone lines are all
burried.

I found out the hard way that burrying the wire doesn't help with lightning
protection when I ran a cat5 ethernet wire from my house to a friends last
year. That thing got zapped evey time we had a bad storm..

- Mike


"Dave Plowman (News)" wrote in message
...
In article ,
Eric Law wrote:
System is balanced and isolated in US too. The ground is just for surge
/ lightning protection.

Right. Few telephone cables in the UK are overground, so that explains it.
The surge arrestor here is just wired between the incoming pair.

--
*Time is fun when you're having flies... Kermit

Dave Plowman London SW
To e-mail, change noise into sound.

"Michael Kennedy" wrote in message
. ..
It is used for lightning protection.. Believe me you really need if you
happen to live in Florida.

- Mike
OR Colorado WW



"Dave Plowman (News)" wrote in message
...
In article ,
jakdedert wrote:
The phone drop (two lines) comes in on one side of the house and is
grounded to the water supply line which comes in the front of the house
(about of 20' of wire clamped to the pipe where it comes through the
foundation into the unfinished basement).

Could anyone explain why a US telephone cable needs a local ground?
Aren't
they balanced?

The UK system only used a local ground for shared local lines which went
out years ago.

--
*Work like you don't need the money. Love like you've never been hurt.

Dave Plowman London SW
To e-mail, change noise into sound.

"Michael Kennedy" wrote in message
. ..
It is used for lightning protection.. Believe me you really need if you
happen to live in Florida.

- Mike
OR Colorado WW



"Dave Plowman (News)" wrote in message
...
In article ,
jakdedert wrote:
The phone drop (two lines) comes in on one side of the house and is
grounded to the water supply line which comes in the front of the house
(about of 20' of wire clamped to the pipe where it comes through the
foundation into the unfinished basement).

Could anyone explain why a US telephone cable needs a local ground?
Aren't
they balanced?

The UK system only used a local ground for shared local lines which went
out years ago.

--
*Work like you don't need the money. Love like you've never been hurt.

Dave Plowman London SW
To e-mail, change noise into sound.





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Michael Kennedy wrote:
I found out the hard way that burrying the wire doesn't help with
lightning protection when I ran a cat5 ethernet wire from my house to
a friends last year. That thing got zapped evey time we had a bad
storm..

The problem wasn't caused by the ethernet wiring; it was the difference
in ground potential between the two homes.

You should have optically isolated the two ends to avoid the problem.

No I'm not talking a small spark when you plug it in. I'm talking about
lightning hitting the wire during storms. It would arc off the wire when it
wasn't plugged into the arrestor.

- Mike

"Travis Jordan" wrote in message
m...
Michael Kennedy wrote:
I found out the hard way that burrying the wire doesn't help with
lightning protection when I ran a cat5 ethernet wire from my house to
a friends last year. That thing got zapped evey time we had a bad
storm..

The problem wasn't caused by the ethernet wiring; it was the difference
in ground potential between the two homes.

You should have optically isolated the two ends to avoid the problem.

Described by jakdedert is a building all but begging for lightning
damage. For example, a cow stands in an open field when lightning
strikes a nearby tree. The cow is killed. Killed by electromagnetic
fields? Of course not. Killed because cow was part of a path from
cloud, through tree, into earth to earth borne charges maybe miles
distant. The electrically shortest path was not under the cow. It was
up cow's hind legs and down fore legs. Cow was part of a direct
lightning strike from cloud to distant earthborne charges.

Cow could have lived is a halo ground surrounded the cow. That
buried conductor would have, instead, routed electricity around (not
through) cows. The concept is called single point earthing. Cow with
separated legs has multiple earthing connections - therefore dead. Cow
centered in a halo ground has a single point ground.

jakdedert describes here (and previously) utilities (ie mutli-line
phones) entering and earthed more like the cow. Building is even worse
because earthing points are farther apart. Destructive charge can
enter building on telephone line (overhead or underground line) either
from its grounding connection or via utility wire (from nearby struck
tree, from other struck building, or entering via ground rod). That
transient crossed building, destructively through appliances, to obtain
earth via AC electric.

Connecting phone line with a 20' plus ground wire or via pipes
accomplishes little. Wire has impedance. That means earthing from
each incoming utility to a single point earth ground MUST be less than
10 feet. Other features such as no splices, no sharp bends, no solder
joints (on wire or pipe), etc also required to lower impedance. Not
resistance - impedance.

A minimal single point ground is a grounding rod. That means even
incoming cable TV wire must make that 'less than 10 foot' earthing
connection to earthing electrode. Better earthing is a halo ground
(what saved the 'dead' cow) or even better, Ufer ground.

What does a protector do? A protector only connects from AC electric
or phone lines (that cannot be earthed directly) to an earthing
electrode. Protector is nothing more than an connection. No earth
ground means an ineffective protector - which many overpriced, plug-in
protector manufacturers hope you never learn. Plug-in protectors that
have no earthing connection, then, connect to what? They hope youj
never ask that question.

Cable TV does not need protectors which often degrade cable modem or
TV signal. Cable is earthed directly - hardwired - to earth without
any protector for superior protection. Wire does better than a
protector.

An electric utility demonstrates bad, good, and ugly earthing. Ugly
because the earthing electrode must be 'lengthened' so that all
utilities make a common earthing point:
http://www.cinergy.com/surge/ttip08.htm

Water pipe typically is not good earthing. Pipes too long, too far
away, too many sharp bends, solder joints, etc. A major difference
between earthing for human safety verses earthing for transistor
safety. A major difference between resistance and impedance means wire
distance is more critical that a low resistance ground. Worse,
jakdedert describes grounding to pipes or water faucets. That means
ineffective and multi point earthing - that also killed the cow.

Most critical component in a lightning protection system is earthing.
Earthing defines uality of that protection 'system' and effectiveness
of protectors. Ineffective plug-in protectors avoid all mention of
earthing to sell hyped products at higher profits. Such ineffective
products have no dedicated earthing connection AND avoid earthing
discussions to keep customers ignorant. Bottom line: a protector is
only as effective as its earth ground.

Effective protector manufacturers have names such as GE, Polyphaser,
Square D, Intermatic, Siemens, Cutler-Hammer, and Leviton. Their
effective products have that dedicated earthing wire.Notice that names
such as APC, Tripplite, Belkin, and Monster are specifically not
mentioned. The telephone company already installs an effective 'whole
house' protector in their NID (premise interface) box. But again, you
(the owner) define its effectiveness by providing an earthing system.

UK residents who suffer so few lightning storms also suffer frequent
and unnecessary damage. This because UK incoming phone lines don't
have that necessary earthing. BT does install effective earthed
protectors on their end. But subscribers are expected to pay for their
own protection - which is provided free in North America.

Also is a myth that underground wires are better protected. Does not
matter as demonstated by the 'dead' cow. Any utility that does not
first connect to single point ground before entering a building is an
obvious incoming path for household electronics damage. As the
'dead' cow demonstrates, single point earthing means even a nearby
lightning strike can be a direct strike into building electronics - if
building's earthing is not properly installed and connected to by every
incoming utility wire.

Damage could have been from voltage potential between different
buildings OR from buried wire carrying transient from a nearby struck
tree. Multiple sources of damage - all due to a building owner who did
not install the most critical component in a protection 'system':
single point earth ground. Why does a telco Central Office, connected
to every other building in town by copper wires, not suffer damage?
The solution has been standard for so many generations - proven
multiple generations before transistors were created. Protection is
and is defined by earthing. Even protectors are only as effective as
their earthing.

Travis Jordan wrote:
Michael Kennedy wrote:
I found out the hard way that burrying the wire doesn't help with
lightning protection when I ran a cat5 ethernet wire from my house to
a friends last year. That thing got zapped evey time we had a bad
storm..

The problem wasn't caused by the ethernet wiring; it was the difference
in ground potential between the two homes.

You should have optically isolated the two ends to avoid the problem.

w_tom wrote:
Described by jakdedert is a building all but begging for lightning
damage. For example, a cow stands in an open field when lightning
strikes a nearby tree. The cow is killed. Killed by electromagnetic
fields? Of course not. Killed because cow was part of a path from
cloud, through tree, into earth to earth borne charges maybe miles
distant. The electrically shortest path was not under the cow. It was
up cow's hind legs and down fore legs. Cow was part of a direct
lightning strike from cloud to distant earthborne charges.

Cow could have lived is a halo ground surrounded the cow. That
buried conductor would have, instead, routed electricity around (not
through) cows. The concept is called single point earthing. Cow with
separated legs has multiple earthing connections - therefore dead. Cow
centered in a halo ground has a single point ground.

jakdedert describes here (and previously) utilities (ie mutli-line
phones) entering and earthed more like the cow. Building is even worse
because earthing points are farther apart. Destructive charge can
enter building on telephone line (overhead or underground line) either
from its grounding connection or via utility wire (from nearby struck
tree, from other struck building, or entering via ground rod). That
transient crossed building, destructively through appliances, to obtain
earth via AC electric.

Yes, I've had problems which I have detailed here before. Still, the
above (and snipped portions) still beg the question: It's gonna be at
least 20 feet of copper between the service and ground. Still better to
single point? That's the 'hit' I'm getting....

Anything would be better than what we have, right? Upgrade the ground
conductor? I've read (here?) that 1/8" copper tubing is superior to the
(looks like) 12 ga. wire currently used in the phone and power grounds.

From the above, I'd assume that 'anything' I did to lower (and
equalize?) the impedance to ground would be--even though not ideal--at
least an improvement. How about multiple ground rods, one at each
service drop--connected together with the aforementioned tubing?

I know that if I could get the telco to drop the lines in between the
cable and power drops, the job would be significantly simplified...and
yes, I have a 100'+ oak tree within 20' of the house.....

jak

'Tree' does not mean it must be a tree. Lightning could strike a
rock, a neighbor's house, a transcontinential pipe line, or even a
water box to create same effect. Earthing is the one solution always
required even if lightning strikes something distant or if lightning
strikes street utility wires.

Upgrade the ground conductor? I've read (here?) that 1/8" copper tubing
is superior to the (looks like) 12 ga. wire currently used in the phone and
power grounds.

Did you view 'bad, good, and ugly' figures from cinergy.com? That
earthing (in this case a 'right' solution) must conform to two masters.
One, for earthing transients (ie lightning). Two, to meet electrical
code defined in NEC Article 250 Section III (Artcile 250.50 through
250.70. Section III defines seven types of grounding electrodes and
numbers that apply including wire sizes.

For example, install a ground ring terminated by rod electrodes (8+'
copper clad steel rod). Since that ground ring has a ground rod where
each utility enters, then each utility can make a 'less than 10 foot'
connection to top of ground rod. Each rod is the same, large, single
point ground.

Code demands a ground ring be 2 AWG bare copper wire buried at least
30 inches. From your perspective, this so that ground wire is below
frost and remains in soil of constant humidity. Suggested is to obtain
of copy those five pages from an National Electrical Code book (maybe
in the library) to better appreciate what is required of each (of seven
type) electrodes.

Above to meet code. However grounding wires (to attach to that
single point ground) also must not have splices, no sharp bends, not
inside metallic conduit, routed away from all other non-earthing wires,
and must be firmly attached with proper connectors - for conditions
beyond what code requires. Best that all earthing wires remain
separate until all meet at the single point earth ground. Don't worry
about exceeding wire diameter. Worry more about wire length. Every
foot shorter than 10 feet means less electricity from lightning will
seek earth ground via household electronics.

Next part of that system would connect every wire from every incoming
cable to that earth ground. Telco has a protector from each (of two)
wires in cable to the ground wire. AC electric has three wires - only
one connects to earth directly. Therefore 'whole house' protector (see
manufacturer list that includes GE, Square D, etc) in AC mains box
connects other AC wires to that earthing wire.

Coax for cable TV and satellite dish use a ground block ($2 available
in Home Depot, Radio Shack, and Lowes) and 10 AWG wire for earthing.

jakdedert wrote:
Yes, I've had problems which I have detailed here before. Still, the
above (and snipped portions) still beg the question: It's gonna be at
least 20 feet of copper between the service and ground. Still better to
single point? That's the 'hit' I'm getting....

Anything would be better than what we have, right? Upgrade the ground
conductor? I've read (here?) that 1/8" copper tubing is superior to the
(looks like) 12 ga. wire currently used in the phone and power grounds.

From the above, I'd assume that 'anything' I did to lower (and
equalize?) the impedance to ground would be--even though not ideal--at
least an improvement. How about multiple ground rods, one at each
service drop--connected together with the aforementioned tubing?

I know that if I could get the telco to drop the lines in between the
cable and power drops, the job would be significantly simplified...and
yes, I have a 100'+ oak tree within 20' of the house.....

w_tom wrote:
'Tree' does not mean it must be a tree. Lightning could strike a
rock, a neighbor's house, a transcontinential pipe line, or even a
water box to create same effect. Earthing is the one solution always
required even if lightning strikes something distant or if lightning
strikes street utility wires.

snip

Thank you, Tom...I think. I'll have to reread your post several times
to get the gist of what you're saying. I'll also do some (more)
research and get the relevant parts of the Code.

'Tree' in this case does mean a tree...a big one, the highest single
point on my entire street...even though there are houses which sit
considerably higher than mine. This is one big tree...probably at least
part of the reason I seem to be plagued.

jak

On Tue, 09 May 2006 10:41:48 -0500, jakdedert
wrote:

I've read a good deal about the above. Ideally, the grounds for various
(telephone, cable, power) electrical utilities should all be common; and
the service entries for those sundry services should be located within
15' of each other.

If I ever build a new house, I will take that into account.

However, it's not practical at this time to realize the ideal. What I
have currently is as follows:

The phone drop (two lines) comes in on one side of the house and is
grounded to the water supply line which comes in the front of the house
(about of 20' of wire clamped to the pipe where it comes through the
foundation into the unfinished basement).

The power drop (100 amp 220v single-phase) enters at the back of the
house, about 30' diagonally from the phone service. A ground wire
snakes from the panel (inside a utility porch) around a couple of
corners and through the floor to a ground post of unknown length/depth
in the crawl space beneath the adjacent kitchen...approximately 20 feet
of wire with at least two 90 degree bends.

The cable drop is around 15' feet from the power service entrance, and
grounded to an adjacent outside faucet a couple of feet away (all
plumbing in the house is copper).

Over the years, we've had a good deal of surge and lightning related
damage to devices in the house...most recently a DSL modem.

Would I derive any advantage by driving a new ground post outside,
adjacent to the power drop and to run all the various service grounds to
it (around 15' for cable, 25' or so for phone)?

Alternatively, I could move the telephone ground wire to the existing
power drop ground post (probably using the same 20' wire), and also
extend cable ground to this point. That would give me a 'star'
configuration with all utilities having around 20'-30' of wire from each
drop to ground.

Moving the phone service drop at this time (the ideal) is not practical.

I'm assuming the DSL modem and computer are plugged into the same
outlet . . .

It sounds like you have two unknown grounds that are far from the
ideal. You don't say what the failure mode of the equipment is and
how severe - I'm guessing it is probably common-mode developing
between the two ground systems. If you get something like bridge
rectifiers in power supplies shorting - that could indicate a
differential voltage spike.

Or, better yet, start at the beginning . . .Check the power
transformer. There should be a lightning arrestor for the transformer
- a kind of insulator that sits off to the side of the can that is
clamped to the can and has a small 1/2"-1" air gap between it and the
HV terminal. (designs vary quite a bit but it should be there in some
form - a collection of broken porcelain around the base of the pole
and some carbon blocks means it is done its job once too often)

The transformer pole and transformer must be grounded. There should
be a thick soft copper wire running from the transformer down the
length of the pole and into the ground. Usually the wire is wrapped
in a spiral and nailed to the bottom of the pole.

Without the transformer grounded - anything you do may be wasted
effort. I had no problem getting a neighbor's lightening arrestor
replaced with just a call to the power company and, in another
instance, a pole ground wire replaced - they are subject to being
stolen by people trying to salvage the copper. Two different power
companies and no arguments - they just went out and fixed it.

Your best option is probably to get the grounds on the same circuit.
I'd sink a ground and wire to it, so I knew what its condition is
like. (ten foot length of half inch dia copper water pipe washed into
the soil is better than anything you're likely to drive into the
ground) Braze or solder the heavy wire on. Put it at the power
entrance as directly under the power meter as you can with no bends in
the heavy wire. Five or six feet to ground if you can manage it with
no bends. Use a large radius bend if you go around an obstacle. It
may not be practical, but do the best that the conditions allow.

What to do about the telephone line and power line separation? Sink
a separate ground for the phone line and just use it for the
lightening arrestor on the line and make sure it is bonded to the main
power ground. There was some good stuff in an ARRL article some years
ago that mentioned a similar problem. He solved it by adding a ground
for the phone line directly under the phone's entrance box to the
company supplied arrester then added a set of gas filled spark gaps in
addition to the arrester.

Cold water pipes are iffy - they can be excellent grounds or very poor
grounds. Too many variables - you'd have to know the material and
condition of the pipe, how straight the run to ground is, and what the
joints are like electrically. Some old systems used cast iron pipe
and the joints are not connected electrically. Some really old cities
still pull up a wooden water main from time to time . . . Galvanized
threaded joints are usually pretty good if the pipe was clean when the
pipes where joined and someone didn't get carried away with Teflon
tape.

Beyond that you can still get fancy with isolation transformers or
optical links.

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We had been through this before in alt.engineering.electrical. Those
who once strongly advocated 'point of use' protectors (ie ex-GE
employees) have backed off that recommendation. One example is an IEEE
paper by them about an "Upside Down House". Francois Martzloff and
Thomas Key in 1994 wrote in "Surging the Upside-Down House: Looking
into Upsetting Reference Voltages" :

Conclusion:
1) Quantitative measurements in the Upside-Down house clearly
show objectionable difference in reference voltages. These occur
even when or perhaps because, surge protective devices are
present at the point of connection of appliances.

Why do those who once always advocated only 'point of use'
protectors now change their tune?

Effective protection at the appliance is already inside appliance.
If components inside 'point of use' or plug-in protectors were so
effective, then those $0.05 parts would already be inside each
appliance. Once they were installed. But since those parts (currently
inside plug-in protectors) were not effective inside appliances, then
appliance manufactures use only other well proven techniques
internally.

This internal appliance protection assumes a transient will be
earthed before entering a building. That being the purpose of a 'whole
house' protector that also costs tens of times less money per protected
appliance. If not earthed, then a transient can overwhelm protection
inside appliances. As Martzloff, et al noted, excessive voltage can
occur even "perhaps because, surge protective devices are present at
the point of connection of appliances". Martzloff was once a major
promoter of 'point of use' protectors.

Do we spend $20 to protect every appliance - or do we spend far less
money to enhance earthing? Per dollar, earthing provides major
appliance protection. Point of use protectors - if for no other reason
- cost massive dollars and provides little benefit. Again, if it were
effective, then those same parts costing so little (and selling at
exaggerated profits) would already be inside appliances. Shunt mode
protectors are only as effective as their earth ground. Plug-in
protectors have what for earthing? So instead, plug-in manufacturers
forget to mention earthing (since earthing is not provided by plug-in
protectors) AND forget to mention protection already inside appliances.
Profits are just too large to be fully honest. Protection is
earthing.... the most critical component in every protection 'system'.

How does a shunt mode protector do anything effective when it does
not shunt to earth? Manufacturer hopes we don't ask that question.
Plug-in protector manufacturers, instead, cite protection from
transients that don't typically cause damage - and hope you don't
notice. They hope you never learn why earthing is so critical -
profits being too outrageously high to be fully honest. Even those who
once only recommended 'point of use' protectors are now changing their
tune in IEEE papers - citing advantages of 'whole house' protectors -
that also cost tens of times less money per protected appliance.

Why would an objectionable voltage not exist in a ground ring? Well
repeatedly cited cinergy.com citation shows a bad, good, and ugly
solution. The prefered solution puts everything at a single point.
But the OP does not have every utility approaching a single point.
Therefore an uglier solution is useful. That solution does make the
earthing more conductive. It does provide a single point ground. It
is a major improvement over what he currently has. Others who can plan
a new house must avoid what the OP has - before footing are even
poured. What the OP currently has would explain (and may be reason
for) his many years of electronics damage. Provided is an effective
and easier solution - since utilities don't like changing services
without big buck bills.

Bud-- wrote:
An excellent paper from the IEEE on surge and lightning protection
(which came from a w_tom post) is at;
http://www.mikeholt.com/files/PDF/Li...ion_May051.pdf

Contrary to what w_tom says plug-in point-of-use surge protectors do
provide protection and are recommended in the paper above. All the
electrically interconnected apparatus, like tuner, amp, has to be
connected to the same surge protector. If there are external lines, like
cable TV, the apparatus can still be protected using a multiport plug-in
surge protector that, in addition to the power protection, has through
ports for the cable connection (and/or phone line, LAN connected to
devices not on the same surge protector, ...). Multiport surge
protectors, and how they protect, are described in the IEEE paper.

Another paper is from the NIST
http://www.nist.gov/public_affairs/p.../surgesfnl.pdf
It also recommends point-of-use plug-in surge protectors.

I agree with w_tom that single point grounding for wires entering a
building (also dish antenna) is a very good idea.

(A multiport surge protector provides a local single point ground at
protected equipment.(
,,,

Why don't you get objectionable drop through the ground ring? (Not to
say that the ring isn't a good idea.)

When you talk about a "halo ground", as for your cow, I presume you are
talking about a ground ring. The only use of "halo ground" I have seen
is as in PolyPhaser papers - a conductive ring around a room
ceiling-wall edge, that may or may not be earthed, to counter the field
effects from the down current from a lightning strike on an adjacent
antenna tower.

If cable and power entrance points are separated, it would seem like the
cable could be wired from the its entrance ground block to a 2nd ground
block adjacent to the power service entrance, with a short connection
from the 2nd ground block to the power service grounding electrode
conductor. Cable distribution to the building from the 2nd ground block.
Similarly a secondary phone protector block could be installed adjacent
to the power service. I have never seen this suggested but it seems like
a practical way to get a single point ground.

bud--

w_tom wrote:
We had been through this before in alt.engineering.electrical. Those
who once strongly advocated 'point of use' protectors (ie ex-GE
employees) have backed off that recommendation. One example is an IEEE
paper by them about an "Upside Down House". Francois Martzloff and
Thomas Key in 1994 wrote in "Surging the Upside-Down House: Looking
into Upsetting Reference Voltages" :


Conclusion:
1) Quantitative measurements in the Upside-Down house clearly
show objectionable difference in reference voltages. These occur
even when or perhaps because, surge protective devices are
present at the point of connection of appliances.


This is exactly what a multiport plug-in point-of-use surge protective
device protects against. These are called Surge Reference Equalizers by
the IEEE. Another paper specifically about SREs is
http://www.eeel.nist.gov/817/817g/sp...les/SRE%20link. pdf
This paper is currently available from the NIST in a collection with a
forward by your good buddy François Martzloff (who was an author of this
paper).

I have provided links to an IEEE paper and and 2 NIST papers, all
current, that recommend plug in surge protectors. In previous threads
(and this one) I have not seen any links supporting your view. Its you
against the IEEE and NIST (and a lot of other people).

bud--

default wrote:
On Tue, 09 May 2006 10:41:48 -0500, jakdedert
...
Or, better yet, start at the beginning . . .Check the power
transformer. There should be a lightning arrestor for the transformer
- a kind of insulator that sits off to the side of the can that is
clamped to the can and has a small 1/2"-1" air gap between it and the
HV terminal. (designs vary quite a bit but it should be there in some
form - a collection of broken porcelain around the base of the pole
and some carbon blocks means it is done its job once too often)

The transformer pole and transformer must be grounded. There should
be a thick soft copper wire running from the transformer down the
length of the pole and into the ground. Usually the wire is wrapped
in a spiral and nailed to the bottom of the pole.

Without the transformer grounded - anything you do may be wasted
effort. I had no problem getting a neighbor's lightening arrestor
replaced with just a call to the power company and, in another
instance, a pole ground wire replaced - they are subject to being
stolen by people trying to salvage the copper. Two different power
companies and no arguments - they just went out and fixed it.
...

Default makes an important point. Defined for a house is a 'whole
house' protection system - also called secondary protection. Primary
protection is provided by the utility, as default has described.
Pictures that demonstrate inspection of a Primary protection system:
http://www.tvtower.com/fpl.html

In Bud's cited 1993 paper on 'surge reference equalizer' or
'multiport protector', Martzloff, et al defines a problem common in
most residences where traditional plug-in (point of use) protectors are
used:
Figure 2 shows such an arrangement, where the telephone
port of the Fax machine is assumed by the end-user to be
protected, thanks to the Network Interface Device (NID)
installed by the telephone company, and the power port is
also expected to be protected by the plug-in surge-protective
device installed by the surge conscious end-user. ...

IOW power strip protector simply creates one of many defined
transient problems that contribute to electronics damage:
A difference of voltage appears across the two equipment ports
during the surge event, in particular during the rise time. This
difference of voltage can cause an upset or hard failure if the
equipment has not been specifically designed for that stress.
Thus, separate, uncoordinated protection of each of the two
ports can still leave the equipment at risk.

Suggested by that 1993 paper is a multi-port protector - surge
reference equalizer- that only uses a principle called equipotential.
First, $20+ to protect only one appliance; without conductivity to
earth?

Second, defined are six ports that must be part of equipotential.
A multiport protector must provide equipotential for all ports at a
point inside the room. But as posted back in April - it does not
provide equipotential because some ports are not part of that
equalization technique. Where is concrete floor or linoleum tile
included as part of multiport protection? Where are baseboard heat,
air ducts, wall paint, or furniture included? That paper calls them
'enclosure ports'. Any one port not part of a multiport equalizer
means equipotential is compromised.

To have equipotential inside a room means the entire room must be
constructed to provide equipotential. Therefore we locate
equipotential where equipotential is easy to achieve.

And third, protection must provide both equipotential and a
conductive path to earth. Since neither equipotential nor conductivity
alone is sufficient, then a protection 'system' must do both. That
'point of use' protector provides all but no conductivity - no
effective earthing.

Not only is equipotential compromised in a room not constructed to
provide equipotential. Also the 'system' does not provide necessary
conductivity to earth. All this and $20 or $80 to ineffectively
protect one appliance? How is that effective?

Meanwhile his 1993 paper then moves on to describe another protective
solution:
High-current surges on the power system originating
outside of the user's premises, associated with
lightning or major power-system events, are best
diverted at the service entrance of the premises.
While such a protection is not mandated at present,
trends indicate growing interest in this type of surge
protection. Either the utility or the end-user may provide
a high energy surge arrester at the service entrance.

Described is a 'whole house' protector. Note how it is described:
... are best diverted at the service entrance of the premises.

'Best' protector recommended by Bud's 1993 paper costs about $1 per
protected electronics. It does provide equipotential to every room (by
making the equipotential point beneath the entire house rather than a
point inside one room). And it provides a best conductivity to earth.
Both requirements - equipotential and conductivity - are necessary for
a 'best' solution. Surge reference equalizer ... AND more ... that
is provided for a whole building rather than just for one appliance is
called 'whole house' protection. As that 1993 paper notes, part of
that 'whole house' system is already in telephone NID.

The same author later states in a 1994 paper:
1) Quantitative measurements in the Upside-Down house clearly
show objectionable difference in reference voltages. These occur
even when or perhaps because, surge protective devices are
present at the point of connection of appliances.

Curiously, this interest in a 'whole house' solution coincided with
post 1990 National Electrical Code changes that require earthing an AC
mains breaker box and all other incoming utilities to a common point.
A common earthing point that must be adjacent - a short distance.
Although code is only for human safety, still, those changes make
'whole house' protection more effective and simpler to install. To
provide surge reference equalization - AND more.

What does not change? A protector - the protection 'system' - is
only as effective as its earth ground. A fundamental demonstrated by
IEEE papers cited in that previous April discussion.

The OP (jakdedert) suspects years of electronics damage due to
transients. His earthing system is defined as defective. Earthing
that violates principles of single point earth ground and post 1990
code. Provided were examples from a utility (cinergy.com), further
details in how to create single point earthing for that building, AND
how to connect each utility to that earthing. Connections either by
hard wire or by effective protectors that even cost less - 'whole
house' protectors. Conductors for earthing and those 'whole house'
protectors are even sold in Lowes, Home Depot, and electrical supply
houses. A solution even recommended in Martzloff's 1993 paper and a
following 1994 IEEE paper. A solution that is routine in virtually
every telephone switching station, commercial broadcasting, emergency
response centers, and now in homes constructed to protect household
transistors.

Bud-- wrote:
This is exactly what a multiport plug-in point-of-use surge protective
device protects against. These are called Surge Reference Equalizers by
the IEEE. Another paper specifically about SREs is
http://www.eeel.nist.gov/817/817g/sp...les/SRE%20link. pdf
This paper is currently available from the NIST in a collection with a
forward by your good buddy François Martzloff (who was an author of this
paper).

I have provided links to an IEEE paper and and 2 NIST papers, all
current, that recommend plug in surge protectors. In previous threads
(and this one) I have not seen any links supporting your view. Its you
against the IEEE and NIST (and a lot of other people).

Regarding plug-in surge suppressors - a bunch of crap. Specific comments
on what you said are like arguing with a Scientologist.

The "1993" paper I furnished a link to is part of a NIST "anthology on
surge protection last updated in 2005. Both NIST references are current
on the NIST web site.

The IEEE document is new. It is also your link.

All 3 papers from the NIST and IEEE recommend plug-in surge suppressors.
Two of these papers are overall recommendations on surge protection for
the general public or people involved in surge protection. Apparently
you are smarter than the NIST and IEEE.

One of the authors of the Upside Down House papers you quoted was Arshad
Mansoor. An electrical engineer commented:
"I found it particularly funny that he mentioned a paper by Dr. Mansoor.
I can assure you that he supports the use of suge equilization type
plug-in protectors. Heck, he just sits down the hall from me. LOL."

I have supplied 3 supporting references. You have supplied none. I
eagerly await your link to a reputable source supporting your views.

bud--

Bud - even your own supporting reference recommends the 'whole house'
solution. With every paper you cite, I repsonded with waves of other
papers, testimony from engineers who actually do this work, and
underlying concepts you don't want to touch: equipotential and
conductivity. Your response is to pretend I provided no sources. You
pretend that an industry benchmark in this technology- Polyphaser -
does not even exist.

Pictures from companies that do protection always start with and
center that protection system around earthing. Only plug-in
manufacturers hope others will not learn why earthing is the most
essential part in a protection system:
http://scott-inc.com/html/ufer.htm
http://www.erico.com/public/library/...es/tncr002.pdf
http://www.leminstruments.com/pdf/LEGP.pdf (page 14)
http://www.polyphaser.com/ppc_TD1023.aspx
Multiple I/O port protection, Single Point Ground considerations
First and foremost, there should be only one ground system.
Second, the individual l/O protectors need to be co-located on the
same electrical ground plane. This means establishing a single
point ground system within the equipment building. An ideal way
is the PolyPhaser Bulkhead Panel, PEEP, or Single Point Ground
Panel. The single point ground system will keep all the I/O
protectors at the same level with respect to each other.
Third, the transmitter equipment chassis must be insulated from
conductive flooring and connected to the ground plane using a low
inductive connector.

Planning guide for Sun Server room (page 89)
http://www.sun.com/servers/white-pap...ning-guide.pdf
Lightning surges cannot be stopped, but they can be diverted.
The plans for the data center should be thoroughly reviewed to
identify any paths for surge entry into the data center. Surge
arrestors can be designed into the system to help mitigate the
potential for lightning damage within the data center. These
should divert the power of the surge by providing a path to
ground for the surge energy.

Not even the military (ie 10th Communication Squadron for the Air
Force) recommends plug-in protectors to provide equipotential - the
multiport protector solution. And you own citation says:
High-current surges on the power system originating
outside of the user's premises, associated with
lightning or major power-system events, are best
diverted at the service entrance of the premises.
While such a protection is not mandated at present,
trends indicate growing interest in this type of surge
protection. Either the utility or the end-user may provide
a high energy surge arrester at the service entrance.

Bud - do you read your own citations before posting them? Your own
citation - a paper from Martzloff, et al - even recommends properly
earthed 'whole house' protection. Why are you arguing in defense of
ineffective plug-in protectors? Do you work for a plug-in protector
company? Even factilities that require well proven protection for
generation don't use plug-in protectors. They use a well proven
(nearly 100 years) method described here as 'whole house'. Why do
those who have effective protection not use what you are recommending -
plug-in protectors? Even your own citation notes that 'whole house'
protection is a 'best' solution.

Bud-- wrote:
Regarding plug-in surge suppressors - a bunch of crap. Specific comments
on what you said are like arguing with a Scientologist.

The "1993" paper I furnished a link to is part of a NIST "anthology on
surge protection last updated in 2005. Both NIST references are current
on the NIST web site.

The IEEE document is new. It is also your link.

All 3 papers from the NIST and IEEE recommend plug-in surge suppressors.
Two of these papers are overall recommendations on surge protection for
the general public or people involved in surge protection. Apparently
you are smarter than the NIST and IEEE.

One of the authors of the Upside Down House papers you quoted was Arshad
Mansoor. An electrical engineer commented:
"I found it particularly funny that he mentioned a paper by Dr. Mansoor.
I can assure you that he supports the use of suge equilization type
plug-in protectors. Heck, he just sits down the hall from me. LOL."

I have supplied 3 supporting references. You have supplied none. I
eagerly await your link to a reputable source supporting your views.

bud--

w_tom wrote:
Bud - even your own supporting reference recommends the 'whole house'
solution. With every paper you cite, I repsonded with waves of other
papers, testimony from engineers who actually do this work, and
underlying concepts you don't want to touch: equipotential and
conductivity. Your response is to pretend I provided no sources. You
pretend that an industry benchmark in this technology- Polyphaser -
does not even exist.


I am for a surge suppressor at the power service and a single point
ground. The issue is ONLY whether plug-in surge suppressors are
effective. I don't remember waves of your papers in this thread. I don't
remember any links from you in this thread [one in a different branch
which is irrelevant]. One of my links is from the IEEE. Maybe you didn't
know that is an association of electical and electronic engineers.
PolyPhaser is probably a good reference if you have a transmitter with a
big tower that attracts lightning. If I was a ham I would be very
interested.

Pictures from companies that do protection always start with and
center that protection system around earthing. Only plug-in
manufacturers hope others will not learn why earthing is the most
essential part in a protection system:

Earthing is a good idea. The question is whether plug-in surge
suppressors are effective.

Hot damn - actual links!!!
http://scott-inc.com/html/ufer.htm
I have previously said that Ufer grounds are a lot better than ground
rods. I am on record as for them. Not relevant to surge suppressors.

http://www.erico.com/public/library/...es/tncr002.pdf
What do you know - a transmitter tower site. Most of us do not have a
very tall lightning rod next to our houses. For those of us who don't
expect to protect from a direct lighting strike a Surge Reference
Equalizer will work.

http://www.leminstruments.com/pdf/LEGP.pdf (page 14)
Thanks for the page reference. I assume you mean pdf page 14, not
document page 14. This page is about is measuring the ground resistance
of a Master Ground Bar at a Telco central office. It may surprise you
but few of us have a telephone switch in our basements. Not mentioned is
what the MGB is used for - which is to provide a single point ground
reference for wires entering the room/floor/whatever. I am in favor of
single point grounds. I saw no mention of plug-in surge suppressors not
being effective, although I personally wouldn't use one on a telephone
switch.

http://www.polyphaser.com/ppc_TD1023.aspx
Surprise, surprise - another transmitter tower site. I previously have
said that single point grounds at the service are very important. From
PolyPhaser:
"Another is to provide some form of impulse protector for each of the
equipment's Input or Output (I/O) ports. These ports are usually the ac
power connection, a telephone or control line, and an antenna
transmission line." That is exactly what a Surge Reference Equalizer
does (but not likely inclding a transmitter antenna).


Planning guide for Sun Server room (page 89)
http://www.sun.com/servers/white-pap...ning-guide.pdf

"Page not found" - not uncommon with your links.


Not even the military (ie 10th Communication Squadron for the Air
Force) recommends plug-in protectors to provide equipotential - the
multiport protector solution.

No source link. Sorry, I want to read the original in context.

And you own citation says:

High-current surges on the power system originating
outside of the user's premises, associated with
lightning or major power-system events, are best
diverted at the service entrance of the premises.
While such a protection is not mandated at present,
trends indicate growing interest in this type of surge
protection. Either the utility or the end-user may provide
a high energy surge arrester at the service entrance.


As I said earlier, I agree that a surge suppressor on the power service
and a single point ground reference is a good idea. But if this is one
of my sources it says plug-in surge suppressors work.


Bud - do you read your own citations before posting them? Your own
citation - a paper from Martzloff, et al - even recommends properly
earthed 'whole house' protection. Why are you arguing in defense of
ineffective plug-in protectors?


My references all say that plug-in surge suppressors are effecive;
didn't you read them? One of my sources [IEEE, the best one] was
originally posted by you; do you read your own citations before posting
them? Another of you previous posts had a different link recommeding
plug-in surge suppressors; you must have not read that one either.

The issue is ONLY whether plug-in surge suppressors are effective. My
links show the IEEE and NIST recommend them. Did you see that? You
constantly try to change the subject, but your links are totally
irrelevant or are silent on this issue, as usual.

bud--

Bud-- wrote:
Hot damn - actual links!!!

When it comes to 'as usuals', still not provided are references
that say "plug-in surge suppressors are effecive". No reason is
provided for plug-in protectors to be effective. Equipotential is
only one requirements for effective protection. Equipotential alone
somehow makes plug-in protectors effective? No possible.

Where concepts behind a unique type of plug-in protector is cited
(multiport SRE), still the author instead recommends 'whole house'
protection. Where other citations only show where a plug-in protector
exist, no proof or claim that the plug-in protectors are effective. In
fact, anything that a plug-in protector might do effectively is already
inside the appliance.

Meanwhile other responsibile sources repeatedly cite what is
necessary for protection - earthing. What does that plug-in protector
not provide? Earthing. Why are other highly regarded sources such as
Polyphaser not discussing plug-in protectors? Polyphaser's application
notes discuss effective solutions that provide both 'equipotential' AND
'conductivity to earth'. Both are required. Plug-in protectors do
not provide both which is why plug-in protector manufacturers do not
discuss earthing. No earth ground means no effective protection.
Provided are days worth of reading that promote effective 'whole house'
techniques - both in theory and in practical experience.


To lightning, a commercial radio tower, a utility AC street wire,
television antenna, telco central office, or household appliances are
same. All are paths to earth that may be destructive or made trivial.
Protection is about earthing. Protector - be it a Franklin lightning
rod or a 'whole house' protector - is about connecting a transient
short to earth ground. So much research on how to protect is performed
on transmitter buildings, telephone central offices, etc - same
research subjects mocked by Bud hoping the lurker will believe insults
rather than technical citations.

What does a Surge Reference Equalizers paper claim?
High-current surges ... are best diverted at the
service entrance of the premises. While such a
protection is not mandated at present, trends
indicate growing interest in this type of surge
protection.

Even after studying SREs, earthed 'whole house' protector is cited as
a 'best' solution. So where does anyone make responsible claims for
this SRE plug-in protector? Instead, responsible sources repeatedly
cite earthing as critical to protection - even after discussing merits
of SRE. What does an SRE multiport protector not provide? Earthing.
Each example of effective protection lists no plug-in (point of use)
protectors. Of course. Even the multiport SRE protector had no
effective earthing - which explains why that paper then recommends
earthed 'whole house' protection.

In a previous discussion, Bud apparently did not read an IEEE Green
Book (IEEE 142) quote entitled 'Static and Lightning Protection
Grounding' :
Lightning cannot be prevented; it can only be intercepted or
diverted to a path which will, if well designed and constructed,
not result in damage. Even this means is not positive,
providing only 99.5-99.9% protection. Complete protection can be
provided only by enclosing the object in a complete metal
encapsulation. ...
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 ...

We protect by intercepting or diverting to what lightning seeks -
earth ground. Where is that multiport (plug-in protector) solution
even mentioned? With no effective earthing, then how then can a
plug-in protector be effective? Question that Bud avoids answering.

So tell me again how this multiport plug-in protector intercepts or
diverts? Where are the two functions of protection - equipotential and
conductivity - provided by that plug-in protector? How does a plug-in
protector that costs tens of times more money per protected appliance
somehow out perform well proven 'whole house' techniques? How does it
provide equipotential when the room violates what is necessary for
equipotential? Three more questions that demonstrate why an earthed
'whole house' solution, instead, was advocated.

Martzloff, et al noted that plug-in protectors may even contribute to
damage:
1) Quantitative measurements in the Upside-Down house clearly
show objectionable difference in reference voltages. These occur
even when or perhaps because, surge protective devices are
present at the point of connection of appliances.

To deny all this, and in response to a first citation, Bud says:
I have previously said that Ufer grounds are a lot better than ground
rods. I am on record as for them. Not relevant to surge suppressors.

Not relevant? Earthing defines effective protection as even
described by IEEE Green Book. Why claim grounding is "not relevant to
surge suppressors"? Hundreds of citations note earthing as essential.
An abridged summary list was posted on 30 Mar 2005 in
alt.comp.periphs.mainboard.asus at:
http://makeashorterlink.com/?X61C23DCA

Then we have this backtracking:
For those of us who don't expect to protect from a direct
lighting strike a Surge Reference Equalizer will work.

Why waste money on a SRE type plug-in protector? Protection inside
appliances already makes trivial transients irrelevant. Why install
protection for something that does no damage? Damage is typically
created by direct strikes that overwhelm protection already inside
appliances. Direct strikes to a tall tower, or to utility wires down
the street, or even from GPR due to a nearby struck tree. All can be
direct lightning strikes to household electronics. Do we spend $20 or
$80 for each household appliance - spending thousands of dollars? Of
course not. Instead, spend about $1 per appliance for an effective,
well proven, residential 'whole house' protector. A solution
demonstrated in transmitter tower sites, server rooms, telephone
switches, airports, and military bases.

Where are these responsible industry professionals who put a multiport
protector in a room - and claim effective protection? None have been
cited. Meanwhile a paper on the Upside Down house says:
1) Quantitative measurements in the Upside-Down house clearly
show objectionable difference in reference voltages. These occur
even when or perhaps because, surge protective devices are
present at the point of connection of appliances.

Same author who recommends 'whole house' protectors in your cited
paper on SRE (point of use or plug-in) protectors also says plug-in
protectors may even contribute to damage. Yes, we demonstrated same by
tracing how a transient entered and left a computer network. A plug-in
protector provided more destructive paths through a computer -
contributed to damage. Since that shunt mode protector provides no
earthing, then a surge must go somewhere - such as destructively
through an adjacent computer.

We learned about protection from transmitter sites and other high
tech facilities. Where was early protection research conducted? On
the Empire State Building during lighting strikes to transmitters.
Lessons there proved how to best protect even homes. So why mock
technical papers from those locations? Best knowledge for household
protection comes from those commercial venues - as so repeatedly
demonstrated by reams of citations.

Shame on Bud for totally misrepresenting what Polyphaser said.
Polyphaser - a highly respected industry standard - is not recommending
an equipotential solution from a SRE type, plug-in protector. Claiming
that Polyphaser supports SRE claims means Polyphaser's paper was not
read:
The protection on each of the l/O's at the building entrance
is good practice and has the advantage of keeping the strike
energy toward the outside of the building and away from the
transmitter.

What was misrepresented as Surge Reference Equalizers (SRE) is
actually 'whole house' protection. Polyphaser does not recommend
ineffective solutions. SRE is protection only using 'equipotential' -
ineffective. Polyphaser discusses protection using 'equipotential' AND
'conductivity'. Effective solution is also called 'whole house'
protection.

The protector will shunt the majority of the strike energy to the earth ground.

How does one completely misrepresent that Polyphaser statement?
Polyphaser states 'shunt' and 'earth ground'. 'Whole house' solution
could not be more obvious. Meanwhile Polyphaser defines additional
criteria for protection:
Another complication in this scenario is the inductance of the
conductor between the I/O protector and the ground system.
The inductance will determine how much of the strike energy
is conducted into the ground system.

And again, connection to earth must be short - ie 'less than 10
feet'. What connection to earth is provided by a multiport, SRE,
plug-in protector? Oh. Earthing is not even mentioned until his paper
then recommends a different 'best' 'whole house' solution. A
solution that provides both equipotential and conductivity to earth is
not SRE advocated by Bud. Plug-in protectors remain unproven, are
demonstrated ineffective, and can even contribute to adjacent
transistor damage.

Another source: IEEE Red Book (Std 141) also recommends protection:
In actual practice, lightning protection is achieve by the
process of interception of lightning produced surges,
diverting them to ground, and by altering their
associated wave shapes.

So where is this 'point of use' or plug-in solution recommended? As
with all responsible citations for effective protection, earthing - not
some multiport plug-in protector - is constantly recommended and
discussed. How do we protect homes? We learn from radio transmitter
stations, telephone switching office, emergency response centers,
maritime communication stations, server rooms, and all those other
facilities that were mocked instead of learned; that cannot suffer
surge damage.

Finally Montandon and Rubinstein wrote a 4 Nov 1998 IEEE paper
entitled "Some Observation on the Protection of Buildings Against the
Induced Effects of Lightning". A direct strike to a building can
create induced effects inside that building:
Equipotential is a technique used to reduce potential
differences between different point, be it within a
building, on a printed circuit board ... The idea is to
establish a "low impedance" path between the points
whose potential is to be equalized. The connection,
called the equipotentialization network, is made using
either wires or metallic grids.

As usual when demonstrating protection even for homes, Montandon and
Rubinstein use a telecommunication building with adjacent antenna
towers. Yes, another transmitter tower site. With grasp and
experience rather than mocking citations ("Surprise, surprise - another
transmitter tower site."), then one learns concepts. Montandon, et al
conclusions for equipotential as a solution eliminates SRE as a
solution:
1) ... a single entry point should be used for all
incoming services in order to avoid that part of
the lightning current flows through the building
as illustrated in Fig 9.

Figure 9 demonstrates problems created when utilities don't enter at
a common point - a building wide common point and not some protector
inside a room.

2) ... large loops should be avoided by suitable
cable routing inside the building.
3) Do not establish equipotentialization by mutliple
bonding of sensitive power or data cables to
different potential reference points within a
structure. ...
4) Follow within the building a bonding and routing
concept to interconnect different equipment by
power and data cables according to the
principles in Fig 12.

So where is equipotential established by point of use (plug-in)
protectors? Demonstrated are problems created by improper cable entry
to buildings, multiple bonding, and improper routing and bonding to
ground. Solutions require lower impedance and better conductivity.
SRE plug-in solution in a room does none of this. Due to current flows
through everything within a building (that makes the SRE solution
impossible), Montandon, et al demonstrate equipotential; better
achieved by routing, bonding, and lower impedance. Same solutions that
other citations discuss. Solutions that demonstrate why 'whole house'
protection (that also costs less) is so effective. Solutions that
demonstrate why plug-in protectors must avoid earthing discussions.
Once we apply missing facts, then every claim of effective plug-in
protector collapses. Plug-in protectors are not reliable protection.
But they do cost more money.

Repeatedly cited is that need for earth ground - a system that
provides both equipotential and conductivity. SRE plug-in protector
would do equipotentialization poorly even according to Montandon and
Rubinstein's paper.

Bud-- wrote:
...
I am for a surge suppressor at the power service and a single point
ground. The issue is ONLY whether plug-in surge suppressors are
effective. I don't remember waves of your papers in this thread. I don't
remember any links from you in this thread [one in a different branch
which is irrelevant]. One of my links is from the IEEE. Maybe you didn't
know that is an association of electical and electronic engineers.
PolyPhaser is probably a good reference if you have a transmitter with a
big tower that attracts lightning. If I was a ham I would be very
interested.
...

Earthing is a good idea. The question is whether plug-in surge
suppressors are effective.

Hot damn - actual links!!!
http://scott-inc.com/html/ufer.htm
I have previously said that Ufer grounds are a lot better than ground
rods. I am on record as for them. Not relevant to surge suppressors.

http://www.erico.com/public/library/...es/tncr002.pdf
What do you know - a transmitter tower site. Most of us do not have a
very tall lightning rod next to our houses. For those of us who don't
expect to protect from a direct lighting strike a Surge Reference
Equalizer will work.

http://www.leminstruments.com/pdf/LEGP.pdf (page 14)
Thanks for the page reference. I assume you mean pdf page 14, not
document page 14. This page is about is measuring the ground resistance
of a Master Ground Bar at a Telco central office. It may surprise you
but few of us have a telephone switch in our basements. Not mentioned is
what the MGB is used for - which is to provide a single point ground
reference for wires entering the room/floor/whatever. I am in favor of
single point grounds. I saw no mention of plug-in surge suppressors not
being effective, although I personally wouldn't use one on a telephone
switch.

http://www.polyphaser.com/ppc_TD1023.aspx
Surprise, surprise - another transmitter tower site. I previously have
said that single point grounds at the service are very important. From
PolyPhaser:
"Another is to provide some form of impulse protector for each of the
equipment's Input or Output (I/O) ports. These ports are usually the ac
power connection, a telephone or control line, and an antenna
transmission line." That is exactly what a Surge Reference Equalizer
does (but not likely inclding a transmitter antenna).
...

As I said earlier, I agree that a surge suppressor on the power service
and a single point ground reference is a good idea. But if this is one
of my sources it says plug-in surge suppressors work.
...

My references all say that plug-in surge suppressors are effecive;
didn't you read them? One of my sources [IEEE, the best one] was
originally posted by you; do you read your own citations before posting
them? Another of you previous posts had a different link recommeding
plug-in surge suppressors; you must have not read that one either.

The issue is ONLY whether plug-in surge suppressors are effective. My
links show the IEEE and NIST recommend them. Did you see that? You
constantly try to change the subject, but your links are totally
irrelevant or are silent on this issue, as usual.

Bud-- wrote:
The issue is ONLY whether plug-in surge suppressors are effective.

If plug-in protectors were so effective, then why do responsible
sources and responsible manufacturers instead discuss earthing and
'whole house' protection? Why then from that paper and from an author
that discusses SRE; his own papers discuss superior and properly
earthed 'whole house' solutions AND note that adjacent plug-in (point
of use) protectors may even contribute to damage?

The issue is effective protection. Two types of protectors exist.
Series mode and shunt mode. Series mode protect by stopping, blocking,
or absorbing surges. Series mode protectors are not discussed here.
Shunt mode protectors work by intercepting or diverting - words right
out of the IEEE green book. SRE is a shunt mode protector.

So where is its earth ground connection? What does multiport SRE
divert (shunt) to? Into adjacent electronics? What kind of protection
is that? From generations of experience and without being part of a
complete room solution: ineffective.

Somehow a multiport, SRE, plug-in (shunt mode) protector will work by
only doing equipotential; by not doing conductivity? Equipotential
does not work in a room that does not bring every one of six ports to a
single point? Defined in that paper is one port that violates SRE
effectiveness: enclosure port.

And finally, one will spend tens of times more money per protected
appliance for this shunt mode protector that does not shunt to earth?
More money for inferior protection that is even too close to
transistors? These are damning questions demonstrated by reams of
citations (IEEE papers, experience from industry professionals, lessons
learned even on the Empire State Building, those so highly regarded
application notes from Polyphaser, etc) on effective protection.

The bottom line fact remains: a protector is only as effective as
its earth ground. A shunt mode protector must make the short (low
impedance) connection to a single point earth ground. This solution
provides both conductivity and equipotential; both necessary because
neither is sufficient. An SRE solution (using a shunt mode protector)
inside a room not specifically constructed to provide equipotential
just does not work. And so even those authors of the SRE paper move on
to discuss a 'best' 'whole house' solution.

Reasons why the SRE is not effective:1) shunt mode protector that
does not provide conductivity to earth, 2) attempts equipotential in a
room that violates that principle, 3) defined in a paper that then
defines a 'whole house' solution as better, 4) costs tens of time more
money, 5) would already be inside an appliance if so effective, 6)
attempts to intercept or divert a surge too close to transistors - a
problem identified and solved in transmitter tower sites and telephone
switching centers so many generations ago, 7) and completely ignores
what has long been demonstrated the most essential component in an
effective protection 'system': single point earth ground.

Somehow this SRE would have eliminated what killed the cow? Yes,
only if the room was part of the SRE solution - a faraday cage. Rooms
just are not constructed to make that possible. Shunt mode protector
that is effective must provide both equipotential and conductivity -
because neither alone is sufficient.

How does electronics get best protected - and at least cost?
Building is constructed with an Ufer ground. Best protection starts
with architect's prints. We still don't build as if transistors exist.
So we earth as best we can after not having done a superior solution
up front. Protection 'system' is only as effective as its earth
ground. Plug-in protector manufacturers hope we never learn that fact.

w_tom wrote:

If plug-in protectors were so effective, then why do responsible
sources and responsible manufacturers instead discuss earthing and
'whole house' protection?

Why does my home insurance company want me to not only have whole house
surge protection but also use power strip surge protectors?

Why has Consumer Reports recommended power strip surge protectors?
They employ several electrical engineers.

w_tom wrote:

If plug-in protectors were so effective, then why do responsible
sources and responsible manufacturers instead discuss earthing and
'whole house' protection? Why then from that paper and from an author
that discusses SRE; his own papers discuss superior and properly
earthed 'whole house' solutions AND note that adjacent plug-in (point
of use) protectors may even contribute to damage?


As I have said, surge protection at the power service entrance is a good
idea. But the issue is ONLY whether plug-in surge suppressors are
effective. "That paper and from an author" - what paper and what author.
What "responsible sources and responsible manufacturers". As always, you
have no links that directly address plug-in surge suppressors. And then
you change the subject.

How about larry moe 'n curlys insurance company and Consumer reports.
Are they "irresponsible"? Its you against the world, and now even
against larry moe n' curly.



The IEEE paper, referenced several times previously is
http://www.mikeholt.com/files/PDF/Li...ion_May051.pdf
- this is YOUR paper
- the title is "How to protect your house and its contents from
lightning: IEEE guide for surge protection of equipment connected to AC
power and cummunication circuits"
- much of its concern is 'transistor safety' - your favorite
- it was published by the IEEE in 2005
- the IEEE is the dominant organization of electrical and electronic
engineers in the US and the publisher of some of your references
- the 5 authors have broad experience with surge suppression

Question:
If plug in surge suppressors are not effective, why does the paper,
divided into 7 sections, contain
section 5: Multi-port point-of-use (plug-in) protectors
section 6 Specific protection examples (all using SREs)
Place your answer in a separate post from other responses. I guess in
your excitement you forgot to explain this.

bud--

Bud-- wrote:
...
Question:
If plug in surge suppressors are not effective, why does the paper,
divided into 7 sections, contain
section 5: Multi-port point-of-use (plug-in) protectors
section 6 Specific protection examples (all using SREs)
Place your answer in a separate post from other responses. I guess in
your excitement you forgot to explain this.

From Section 5 of a Mike Holt paper cited by Bud:
An additional feature ... if they are properly used,
is that all surge currents which come in from AC
wiring and signal connections (both active wires
and grounds) are disposed of via the AC ground,
back to the building ground.

What is performed by both plug-in protectors and 'whole house'
protectors? Where does every buck spend provide (enhance) protection?
Where does labor and parts result in significant transistor safety?
Among many points - plug-in protectors cost massively more for
inferior, if any, protection. Either we spend and enhance effective
'whole house' protection, or we waste time and money on protectors
from less responsible manufacturers. Less responsible? Show me where
a plug-in manufacturer even claims protection from transients that
cause damage? You cannot. Plug-in manufacturers do not make that
claim. Where are the numbers listing each type of transient? Not
provided.

Every cited paper - and now we add Mike Holt to the list - does
not blindly recommend plug-in protectors. These papers discuss merits
(pluses and minuses) of such protection; noting inferiority problems
using plug-in protectors. Spend tens of times more money and still
get less - if any - protection? Why does Mike Holt say,
"properly used"? He demonstrates numerous problems with plug-in
protectors. Below is a sampling of why plug-in protectors are
compromised AND can even contribute to adjacent appliance damage.

Figure 8 shows a plug-in protector adjacent to TV1. How much voltage
difference between that protector and earth? 8000 volts. Is that TV
going to charge up to 8000 volts and not find other, destructive paths
to earth? Of course not. 8000 volts can find paths - some
destructive - to earth via appliance. 8000 volts again demonstrates
why protection must be located at service entrance - why plug-in
protectors are not effective. Mike Holt makes a specific reference to
"properly used", and demonstrates why plug-in protectors can even
contribute to damage of adjacent electronics.

How curious? A point 1 in that Martzloff, et al paper says same
thing:
1) Quantitative measurements in the Upside-Down house clearly
show objectionable difference in reference voltages. These occur
even when or perhaps because, surge protective devices are
present at the point of connection of appliances.

Mike Holt puts numbers to an objectionable voltage - 8000 volts.

How many papers make a same point - that plug-in protectors (that
cost tens of time more money per protected appliance) can even
contribute to electronics damage? Even personal experience by
tracing a surge through plug-in protector and then through powered off
and networked computers was cited. How many times need we cite but
another failure (damage) made easier by plug-in protectors? AND where
does this mean Mike Holt recommends plug-in protectors? Bud - just
because Mike Holt discussed plug-in protectors does not - not for one
minute - mean that Section 5 *recommends* plug-in protectors.
Section 5 demonstrates numerous reasons why plug-in protectors can even
contribute to electronics damage. Mike Holt demonstrates difficulty in
making a plug-in protector effective.

Mike Holt demonstrates what that Martzloff, et al paper also says:
Figure 8 shows a very common improper use of multiport
protectors that does not fully protect against lightning
damage because of this effect. One multiport protector, D,
has been used in an attempt to protect two TV sets. The
installer assumed that the coaxial protector in D would
remove the lightning surge, and any TV sets downstream
would be safe without further protection.

Remember - they are shunt mode protectors. They shunt transients
to earth - to provide both conductivity and equipotential. Mike Holt
also notes what a plug-in protectors must do:
all surge currents ... are disposed of ... back to the building ground.

How curious. The protector works by connection to earth ground. Why
does the plug-in protector manufacturer 1) not provide the dedicated
earthing connection, and 2) does not discuss earthing? Why does
plug-in manufacturer avoid discussing that 8000 volts? That's 8000
volts that will find other earthing paths within the room - except if
the room is constructed as part of the protection.

Why would a plug-in protector connect currents back to an earth ground
that was ignored by that same current at the 'whole house'
protector? Think what is claimed. If earth ground at the 'whole
house' protector cannot earth a transient, then why would that same
transient seek that same earth ground via a plug-in protector? If
current cannot obtain earthing at the 'whole house' protector, then a
transient through a plug-in protector will find other (potentially
destructive) path to some other earthing inside the room.

Where is labor, money, and time better spent? Enhancing service
entrance earth ground; not buying grossly overpriced and ineffective
plug-in protectors. If earthing is not sufficient, then what will
plug-in protectors earth to? Less money better spent fixing the reason
why a transient was not earthed before entering a building. Money
better spent on fixing the real problem - insufficient earthing.

Mike Holt recommends plug-in protectors in Section 5? Au
contraire. Mike Holt cites numerous reasons in Section 5 why plug-in
protectors fail. Martzloff, et al make a same point with 'six
ports'. Any one port violated, then damage can result. How curious
that a Martzloff paper (knowing full well that most every lurker here
will not comprehend these 'six ports') then moves on to recommend a
'whole house' solution.

Will a layman appreciate 'six ports' defined in a Martzloff paper?
Of course not. Yet all 'six ports' must be understood to make a
plug-in protector effective. Mike Holt further defines multiple
reasons why a layman cannot "properly used" plug-in protectors.

Mike Holt demonstrates another plug-in protector problem:
Appropriate signal protectors are available for most
connections, but they must be carefully selected and
matched to the application.
The most obvious requirements are as follows:

Five points are listed. Then Mike Holt describes the problem:
Unfortunately, for most consumer electronics
equipment and protectors, the information to
answer these questions is not readily available.

What is the homeowner to do when information is not readily
available? Instead obtain conductivity and equipotential by properly
earthing effective 'whole house' protectors. Earth trasnsients long
before they get into the room.

BTW, Bud, everyone has a limited budget. $100 or $10,000 does many
times more at the 'whole house' as compared in plug-in protectors.
There is no separation between 'whole house' and plug-in solutions.
It all comes from the same dollar bills. More of one means less of
the other. Plug-in protectors typically cost tens of times more money
for inferior and complicated protection.

Consumer must understand all six ports? Consumer must answer Mike
Holt's five questions? Solution in a room not even designed to be
part of the protection system? No wonder plug-in protector
manufacturers don't say how or why their products work. No wonder
they will not tell you, me, and every lurker what is necessary for a
'point of use' protector - earthing. What did Mike Holt define to
make a plug-in protector effective?
all surge currents ... are disposed of ... back to the building ground.

And because that path is too far, the voltage different is listed in
his figure as .... 8000 volts.

And so again - this time from Mike Holt - we have THE most
critical component in every protection system: **earthing**.

Mike Holt describes how a plug-in protector even causes damage to TV1
and TV2 in figure 8.
Figure 9: Equipment that has its own ground can be
damaged by potential differences between two grounds.

Show me every housewife who will address all those grounding
questions? Most men lurking here don't even fully understand the
concept. And yet that is what Mike Holt demonstrates - what
Martzloff calls the 'six ports'. Any one path to ground not part
of a multiport protector means electronics damage. Or what was
described previously as no equipotential.

Again, a plug-in protector may simply make electronics damage
possible - even to powered off appliances. Just another reason why
effective protection in transmitter tower sites, telephone switching
centers, 911 emergency response centers, etc all put protection at a
single point earth ground AND distant from electronics. Notice that
last phrase: effective protection is located "farther from
electronics".

Where in Section 5 does Mike Holt recommend plug-in (point of use)
protectors. Instead he describes, multiple times over, why plug-in
protectors fail to protect.

Mike Holt describes another problem with plug-in protectors:
Typically, protector manufacturers cite a Joule rating
for the protector that is the sum of the (MOV
manufacturer's) Joule ratings for all the MOVs in the
product, and this has become a sort of "horsepower
race". However, especially in protectors of the 6C
design, the fusing may be set to such a low level that
the fuse opens (eliminating the surge protection) long
before the stated capability of the MOVs is reached.
If this happens, the claimed Joule rating is meaningless.

Why would one recommend spending more money on a plug-in protector
that has so many compromising complications? Even all its MOVs don't
get used in protection. Carefully address everything in Section 5;
what Martzloff calls 'six ports' are necessary to make protection
effective. Even room construction must be considered. Smart money
installs a 'whole house' protector AND enhances the most critical
'system' component: earthing.

Less technical expertise, labor, and money provides a superior
solution - a 'whole house' protector and single point earth
ground. An effective solution even sold under more responsible
manufacturer names such as Cutler-Hammer, Leviton, Polyphaser, Siemens,
Square D, and GE. A solution found in Home Depot, Lowes, and
electrical supply houses. A simpler solution that is standard
protection even in high reliability facilities such as maritime
communication stations, cell phone towers, and every telephone
switching station. Do they use plug-in protectors? Of course not.
They want effective protection - not complications and hype.
Protection is defined by and is as effective as its earth ground.

Every dollar wasted in plug-in protectors is better spent in the
'whole house' solution - especially in earthing.

larry moe 'n curly wrote:
Why does my home insurance company want me to not only have whole house
surge protection but also use power strip surge protectors?

Why has Consumer Reports recommended power strip surge protectors?
They employ several electrical engineers.

Don't ask me why a home insurance company did not first learn the
science. Ask them? If they know a plug-in protector is effective,
then they have provided reams of facts that I did not learn after
numerous decades of doing this stuff. Always looking for new facts -
which is why IEEE always demands reasons 'why'.

I don't see Consumer Reports recommending protectors. What issue?
What date? Why no specific citation or quote? Why is being an
electrical engineer sufficient to be knowledgeable on transient
protection? What kind of assumption is that? Instead post technical
whys and whys nots - with quotes and numbers (technical reasons) from
that article. Why do you think Bud - and rightly so - has trouble
with any citation he cannot read in long and painful detail. Where
are those details from Consumer Reports?

Bud-- wrote:
...
How about larry moe 'n curlys insurance company and Consumer reports.
Are they "irresponsible"? Its you against the world, and now even
against larry moe n' curly.

Sun Microsystems no longer provide their Planning Guide for Sun
Server Room. Therefore you had a problem with it - and rightly so -
because you could not review what Sun recommends in a server room.
Meanwhile larry moe 'n curly provide no date or issue, no numbers, no
direct quotes, .... nothing. And you don't have a problem with that?
Why the double standard? Why was your next post about what could very
easily be nothing more than a rumor - some speculation about a CR
recommendation? He provided no citation, no numbers, and not a single
reason (from CR) why a plug-in protector is recommended. You have no
problem with such posts?

w_tom wrote:
Bud-- wrote:

...
Question:
If plug in surge suppressors are not effective, why does the paper,
divided into 7 sections, contain
section 5: Multi-port point-of-use (plug-in) protectors
section 6 Specific protection examples (all using SREs)
Place your answer in a separate post from other responses. I guess in
your excitement you forgot to explain this.



Every cited paper - and now we add Mike Holt to the list - does
not blindly recommend plug-in protectors. These papers discuss merits
(pluses and minuses) of such protection....

Major progress - IEEE (NIST, ...) now are recognized as recommending
plug-in surge protectors. There are, of course, pluses and minuses for
any protection scheme. Not obvious what other "cited paper" you refer to.

Figure 8 shows a plug-in protector adjacent to TV1. How much voltage
difference between that protector and earth? 8000 volts. Is that TV
going to charge up to 8000 volts and not find other, destructive paths
to earth? Of course not. 8000 volts can find paths - some
destructive - to earth via appliance. 8000 volts again demonstrates
why protection must be located at service entrance - why plug-in
protectors are not effective. Mike Holt makes a specific reference to
"properly used", and demonstrates why plug-in protectors can even
contribute to damage of adjacent electronics.


This paper is not Mike Holt's. It is from the IEEE. Mike only provides a
link to it. If Mike provided a link to the Bible, it would not become
Mike's document.

The IEEE provides this example to show how a SRE can protect the first
TV, and says that protection is effective. The IEEE paper says a second
SRE is needed at the second TV. If the CATV entrance is distant from the
power entrance, as this example describes, there can be a large
difference in the ground potential at the CATV ground block and the
power service ground, 10 kV as this example describes. A single point
ground reference at the power service for all incoming wires is
desirable but not always present.

In additon, the CATV ground block, as you have said, provides no surge
protection for the signal conductor - the limit being the flashover
voltage at connectors. IIRC the IEEE paper said this was about 4 kV,
which could appear at the TV antenna connection. The SRE has surge
protection on this wire, which is not provided in 'whole house'.


How curious? A point 1 in that Martzloff, et al paper says same
thing:


No link, or even name provided for paper. Hey, wasn't that a major issue
for larry moe 'n curly's reference to Consumer Reports??

Even personal experience by
tracing a surge through plug-in protector and then through powered off
and networked computers was cited. How many times need we cite but
another failure (damage) made easier by plug-in protectors?

The whole point of SREs is that they protect against this exact hazard.

AND where
does this mean Mike Holt recommends plug-in protectors? Bud - just
because Mike Holt discussed plug-in protectors does not - not for one
minute - mean that Section 5 *recommends* plug-in protectors.
Section 5 demonstrates numerous reasons why plug-in protectors can even
contribute to electronics damage. Mike Holt demonstrates difficulty in
making a plug-in protector effective.


You need to learn how to read. The IEEE (not Holt) provides section 5 to
show how SREs can provide protection, and follows with section 6 to
demonstrate specific examples of protecting with SREs. To say the IEEE
doesn't recommend SREs is remarkably dense.


Remember - they are shunt mode protectors. They shunt transients
to earth - to provide both conductivity and equipotential.

A MOV clamps the voltage across its terminals. Surge supressors
fundamentally clamp the voltages on the protected wires to a common
reference point. We both agree the ground path fom an receptacle to the
power service panel is relatively high resistance. The protection
provided by plug-in surge supressors is primarily by clamping, the
conduction to earth is secondary. In the fig 8/fig 9 TV example, most of
the earthing of the surge on the CATV service is via the "Coax sheath
ground bond" from the CATV entrance ground block to the power service
entrance (IIRC the paper says that).

How curious. The protector works by connection to earth ground. Why
does the plug-in protector manufacturer 1) not provide the dedicated
earthing connection, and 2) does not discuss earthing? Why does
plug-in manufacturer avoid discussing that 8000 volts? That's 8000
volts that will find other earthing paths within the room - except if
the room is constructed as part of the protection.


The plug-in protector works primarily by clamping. Essentially the whole
problem in this thread is that your religous views recognize only
earthing, not clamping. The IEEE recognizes SREs are effective, thus
action primarily by clamping can be effective.


BTW, Bud, everyone has a limited budget. $100 or $10,000 does many
times more at the 'whole house' as compared in plug-in protectors.
There is no separation between 'whole house' and plug-in solutions.
It all comes from the same dollar bills. More of one means less of
the other. Plug-in protectors typically cost tens of times more money
for inferior and complicated protection.

'Whole house' and single point ground are good ideas.

For power/phone/CATV/... entrances not immediately adjacent you won't
have single point ground. CATV ground blocks don't arrest surges
arriving on signal wire. Surges can arrive in other ways. Plug in surge
protectors can provide protection, as recognized by the IEEE (and others).


Show me every housewife who will address all those grounding
questions? Most men lurking here don't even fully understand the
concept.

Most men (and women) lurking here can read the IEEE paper and understand
it better than you.


Mike Holt describes another problem with plug-in protectors:

Typically, protector manufacturers cite a Joule rating
for the protector that is the sum of the (MOV
manufacturer's) Joule ratings for all the MOVs in the
product, and this has become a sort of "horsepower
race". However, especially in protectors of the 6C
design, the fusing may be set to such a low level that
the fuse opens (eliminating the surge protection) long
before the stated capability of the MOVs is reached.
If this happens, the claimed Joule rating is meaningless.


[The IEEE says Joule ratings are substantially meaningless.] Every
protection scheme is a series of tradeoffs. The circuit of 6B, with the
protected equipment downstream from the fuse, will disconnet the
protected equipment with the MOV. And the manufacturer may or may not
set the fusing to an appropriate level. The IEEE doesn't seem to see
this as a critical problem. Surge protectors installed at the electrical
service also have overcurrent protection which is subject to the same
problem.

================================================== ==============
Another relevant article is
http://www.ecmweb.com/mag/electric_o...ald/index.html
This is an article from "Electrical Construction and Maintenance"
magazine reviewing the book "IEEE Recommended Practice for Powering and
Grounding Sensitive Electronic Equipment" (the Emerald book in the color
book series)

A quoted definition from the IEEE Emeral book is:
"Surge reference equalizer. A surge-protective device used for
connecting equipment to external systems whereby all conductors
connected to the protected loads are routed, physically and
electrically, through a single enclosure with a shared reference point
between the input and output ports of each system."


With comment from the article:
"It has been found that, with multiport loads (such as computers with AC
power input and data communication ports, televisions with AC power and
CATV ports, or fax machines with AC power and telephone ports), a
transient voltage surge event on one port, even if protected by
transient voltage surge suppressor (TVSS), causes a transient voltage
surge to be impressed across the other ports, often causing damage to
the load equipment. One potential solution is the use of a surge
reference equalizer to prevent differences in the ports' ground
references under transient voltage surge conditions."

Fig 8 from the IEEE paper above is repeated in the book, and SREs are
recognized as a tool in protecting electronics - same as the IEEE paper
above.

bud--

This is where disagreement exists.

Bud-- wrote:
A MOV clamps the voltage across its terminals. Surge supressors
fundamentally clamp the voltages on the protected wires to a common
reference point. We both agree the ground path fom an receptacle to the
power service panel is relatively high resistance. The protection
provided by plug-in surge supressors is primarily by clamping, the
conduction to earth is secondary. In the fig 8/fig 9 TV example, most of
the earthing of the surge on the CATV service is via the "Coax sheath
ground bond" from the CATV entrance ground block to the power service
entrance (IIRC the paper says that).

Bud describes differential mode protection. Destructive transients
are common mode. Yes a MOV can clamp (short circuit) a voltage between
two wires. And that transient is typically not destructive.
Differential mode transients are not typically sourced by lightning.
Typically destructive transient is common mode. Clamping between two
wires only puts that common mode transient on both wires - and still
seeking earth ground.

Defined previously were two computers connected to plug-in protectors
and powered off. A destructive transient was clamped by MOVs inside
adjacent protectors. Now that destructive transient has more paths
into the adjacent computer. That transient took paths provided by
clamping in an adjacent protector. Incoming on AC wire. Outgoing on
network. Down network wire to a third computer. Out that third
computer via a modem and phone line to earth ground. Each damaged IC
in that path was replaced; computers worked again.

Adjacent protectors did clamp the transient. Transient was clamped
right into a destructive path through computers. Telephone switching
centers don't put protectors adjacent to electronics for same reasons.
Telco prefers shunt mode protectors to be up to 50 meters away from
electronics - and short distance to earth. Why? As demonstrated
above, clamping adjacent to electronics can even contribute to
electronic damage. Clamping at the earth ground shunts (diverts,
connects, intercepts) a destructive transient to earth long before it
can find earthing paths destructively through electronics.

Fig 8/9 TV example demonstrates but another 'sneak' path that
contributes to damage. Why. Clamping was too close to electronics and
too far from earth ground. Rooms are constructed with 'sneak' paths
everywhere. Just another reason why clamping must be at the earthing
connection. That IEEE paper (previously attributed to Mike Holt)
demonstrates too many ways for a plug-in (point of use) protector to
fail; even contribute to electronics damage.

Shunt mode protectors are effective when shunting (clamping) short to
earth ground. Plug-in protectors (also called shunt mode devices) hope
you never learn about the typically destructive transient AND why
shunting must be both short to earth and distant from electronics.

Bud is describing protection from a transient that typically does not
do damage AND that is made irrelevant by protection already inside all
electronics.

Why is the 'whole house' protector so effective? 1) It shunts or
clamps all types of transients. It does that clamping distant from
electronics. 2) It does that clamping short to earth. It is properly
sized. 3) It connects to what shunt mode protectors need to be
effective: single point earth ground. Not just any ground. A short
connection to single point earthing. Clamping is ineffective if no
earthing to clamp to. Earthing that provides both equipotential and
conductivity. And yes, both conductivity and equipotential are
necessary for shunt mode devices to be effective. MOV not clamping to
earth (above example) even contributed to damage of three networked
computers. I have seen such damage too often to believe plug-in
protectors are worth ten times more money per protected appliance.

Why are 'whole house' protectors so effective? A short connection to
(clamping to) earth ground determines effectiveness. Earthing being
the protection. Protector being nothing more than a temporary
connection (clamping) to protection. Protector being only as effective
as the protection it connects to: earthing.

To provide both conductivity and equipotential, the clamping of a
typically destructive transient is best distant from protected
electronics AND as short as possible to earth. Such protection
effective for all type of transients - and costs many times less money.

Bud-- wrote:
Consumer Reports reviewed surge protectors Nov 1994. I know you want to
look it up to check the statements of larry moe n' curly, but could all
3 of them be wrong?

Consumer Reports did normal mode testing of protectors in 1994. APC
once provided numbers for normal mode transients. But neither that
Consumer Reports test nor APC made any claims about a type of transient
that typically does damage.

CR then made some very abridged claims in 2000. However something
strange happened. Suddenly CR eight year indexes starting 2003 dropped
all references to surge protector reviews. Those 2000 reviews should
remain in the CR indexs until 2008. But by 2003, CR makes those 2000
tests difficult to find. Tests that provide few details and apparently
did not test per how damage typically occurs.

Larry, Moe and Curly did discuss many things. However they also
could not tell us What's on first, Who's on second, and Where is third.
Important questions of that age. Today, we only google for live's
little questions.

Bud-- wrote:
NEVER fly in an airplane. They seldom drag an earthing chain while
flying, leaving their avionics totally exposed to lightning. (I'm sure
there is a major coverup of the frequent plane crashes.)

This discussion was completely about terrestrial protection. But
same principles - conducting lightning to the earth ground (or outgoing
connection) also apply to planes. Aircraft designers have it far more
complex. Unlike a terrestrial building, a single point earth ground
can be anywhere. They must design everything in terms of layers -
layers of earthing - which is well beyond the scope of this discussion.
For example, the earth ground this time in this picture is quite
obvious: plane's tail:
http://www.crh.noaa.gov/pub/ltg/plane_ltg.gif

Next time the outgoing transient path could be anywhere else.
Planes are struck routinely without damage. Same principles that also
define the 'whole house' protector so effective - conducting lightning
in paths that are not destructive. Concepts of equipotential and
conductivity even apply to airplanes. Same concept that must be
applied with greater care due to transients from and to more
directions.

Review that famous picture. Plane conducted direct lightning strike;
no problem.