Date: February 22, 2001
From: barefacedThe thread entitled "Power Surge + Problems" describes
effective surge protection. I have yet to see an APC product that is effective surge
protection. They are sly. For example, in page 5 of this spec: (dead-link
removed) ; no common mode surge protection. They only claim differential (normal)
mode protection. Computer damage comes from common mode surges. They spec no common
mode surge protection.
Do they have surge protection? Yes. Is it effective from destructive surges?
No. Unfortunately, many will recommend surge protection without even the slightest
understanding of surge protection fundamentals.
For example, in another forum, one recommended better surge protection to help avoid
intermittent computer crashes. Why is this bogus? Surges only occur typically about
once every 8 years. Daily computer crashes are not from surges.
Furthermore, if one has daily surges, then the surge protector will be *toast* before
the week ends.
Unfortunately "good" surge protection recommendations often are based only
facts from the 'Joe Camel' and 'Marlboro Man' people. Most "good" surge
protection recommendation comes from people who don't understand the basic concepts.
Plug-in surge protection is typically ineffective as defined by four criteria in that
other post. Suspect ineffective surge protection using this benchmark. If it does not
mention critical earth ground; if it does not have the dedicated earth ground connection;
then it is ineffective surge protection. That benchmark quickly identifies plug-in surge
protection as ineffective.
Every so often, some plug-in surge protection manufacturer will post honest facts in
the fine print. The SL Waber EP63 Power Master uses the same $0.05 and $0.30 components
found in those APC, Tripplite, etc surge protectors. But SL Waber also includes this fine
print: "This Surge suppressor is not a lightning arrestor and may not protect against
lightning induced voltage surges".
Why does the SL Waber not protect from lightning? For the same reason that the other
plug-in surge protectors don't. Unfortunately, many who will recommend surge protection
don't have the EE101 fundamentals to understand why SL Waber prints the above quote.
Surge protectors are built to activate at 330 V or higher. These are surge voltages for
a 120 VAC line. TVs, ovens, and refrigerators do not create surges. Four important points
(not to be confused with the previously posted four criteria that define ineffective surge
protection).
First, if a household appliance created 330+V spikes, then the appliance must be
removed immediately for human safety. At best, an appliance only creates noise transients.
Second, even cheap surge protectors only activate above 330 V. If they activated at
noise levels of appliances, then surge protection would be useless quickly. See the data
sheets for MOVs, for example, to appreciate the problem.
Third, if appliances were creating surges, then surge protection would be installed at
the source - not at all other appliances. Household appliances just don't create surges.
Fourth, surges don't happen daily or weekly. If they did, then we all would troop
weekly to the hardware store for new clock radios, dimmer switches, timer switches, and
portable phone base stations. Surges typically occur about once per 8 years - your local
numbers will vary. In order to create hype and fear, scammers in surge protection are
quick to confuse noise with surges (as well as confuse common mode transients with
differential mode as posted previously).
Direct lightning strikes occur often without any damage. Polyphaser - makes equipment
designed for direct lightning strikes. Polyphaser is THE name that everyone knowledgeable
of surge protection is familiar. Commercial sites install Polyphaser because they must
NEVER suffer surge damage from any and all lightning strikes.
Telephone switching stations also called COS - are connected to overhead wires
everywhere just asking to be struck, must operate during every lightning storm, AND must
never fail in any CO during any lightning storm. Why? Because they use simple surge
protection, properly installed. COs, like properly installed residences, locate surge
protection far from transistors and close to earth ground. COs typically separate the
surge protector 50 meters from their computers.
Empire State Building - is directly struck about 25 times per year. Every one of those
TV and FM broadcasters must operate without damage during every one of those strikes. No
problem because surge protection can protect from direct lightning strikes.
Telephone cell phone towers - could you ask for a more vulnerable structure? Failure is
not an option. A downed tower is loss of $tens of thousands every hour. Furthermore the
tower is required most just after destructive weather - i.e., lightning storms. Cell phone
towers must withstand every direct strike - no problem.
IOW it is normal to have direct lightning strikes without damage.
Previously five different electrical events were defined. Blackout, brownout,
harmonics, surges, and noise. A struck power pole typically creates a blackout. That is
not a surge because surges have completely different electrical characteristics.
Previously defined was heavy and effective surge protection sold in Home Depot. Minimal
spec numbers for residential electric - 1000 joule and 50K amps. Also noted previously is
that the actual rating on plug-in surge protection should be de-rated to 1/3rd of listed
joules - because of plug-in location and design. IOW a plug in surge protector rated at
660 joules may provide as little as 220 joule protection. The 1000 joule 'whole house'
surge protection is expected to withstand as much as 1000 times more surges compared to
the ineffective, plug-in 220 joule (actual) protector. Again this was iterated elsewhere
in greater detail.
Effective surge protection does protect from direct lightning strikes. Plug-in surge
protection is not effective for any (usually all) of four previous criteria. A blackout is
not a surge. Household appliances do not create surges. Anyone familiar with basics of
surge protection also knows THE name - Polyphaser. Polyphaser does not sell plug-in surge
protection because Polyphaser has a reputation of selling effective surge protection.
A classic lesson for all now that lightning season approaches. If the surge protector
died long before the surge was finished, then appliance damage occurred. Myths say that
surge protectors burn up to protect from surges. But surge protectors don't stop or absorb
surges - as myths imply. Surge protectors only shunt a surge from one wire to all others
wires. They must be part of a system.
A surge protector that burns up is grossly undersized - not just undersized. Ironically
that problem also exists with ineffective, brand name surge protectors.
A surge protector that meets any one of four criteria is ineffective: 1) too close to
transistors, 2) too far from earth ground, 3) too expensive to only protect one device
(effective surge protection can cost about $1 per appliance), and 4) too undersized for
effective protection.
Most, if not all, four criteria are found in surge protection sold in CompUSA. Plug-in
surge protection is obviously defined by above as ineffective.
A surge protector is only as good as its earth ground. No earth ground means no
effective surge protection. IOW earth ground must be single digit feet from the surge
protector. Plug-in surge protector violate this critical requirement.
Effective surge protection for residential electric service is sold in Home Depot as
Intermatic EG240RC or Siemens QSA2020. If not found, have a salesman enter either model
number into his computer as a "Part Number". He can tell you how many are in
stock AND what other stores have how many.
Minimal surge protection must be 1000 joules and 50,000 amps. Minimal. If a plug in
surge protector is RATED at 660 joules, then it really only uses as little as 220 joules
in surge protection; and never more than 440 joules. IOW de-rate a plug-in surge
protection by 1/3rd to appreciate its real ratings - just another reason why plug-in surge
protection is so ineffective.
A surge that both damages the adjacent surge protector AND computer: the computer is
now a science project on surge forensics. Much could be learned from the damage
understanding that all surges must have an incoming and an outgoing path.
Every line into every building requires surge protection where the wire enters the
building AND less than 10 feet to the central earth ground. Earth ground is another
critical component of a surge protection **system**. Those plug-in surge protectors are
only one system component - with the rest of the system missing. IOW plug-in surge
protectors represent wasted money.
Just one more point to chew on. Surge protectors adjacent to computers can actually
complete a surge destruction circuit even if the computer is powered off. Yes- a powered
off computer can be damaged because it was plugged into a power strip surge protector.
Now that you are buying new computers on a tax free week, also buy effective 'whole
house' surge protection AND don't waste any money on ineffective plug-in surge devices.
WalMart sells plug moles for less than $2 to replace useless power strip surge protectors.
Expensive surge protectors are often not any better than the cheap ones since a surge
protector is only as good as its earth ground. Plug-in surge protectors have all but no
earth ground.
The basic whole house surge protector can be installed by anyone who can click a
circuit breaker into the fuse box (while the room is dark because the main circuit breaker
is turned off). The Siemens unit is particularly easy because the circuit breaker also
contains the surge protector.
The 'whole house' surge protection is the only surge protection that will be effective.
Plug-in surge protection suffers from many of the four criteria that define ineffective
surge protection.
As for the silly warranty, the newsgroups are full of people who never got their
warranty honored. See, for example, in the newsgroup comp.os.os2.misc a 1 Feb post
entitled "UPS failure, redux." WD Loughman. His frustrations with reimbursement,
I believe data back to last fall. His are typical. Insurance is not surge protection. If
you want surge insurance, then buy it from an insurance company that must comply with
Federal Regulations and therefore will reimburse you.
Plug-in surge protection is ineffective. Two minimal surge protection devices at Home
Depot are Intermatics EG240RC and Siemens QSA2020 - less than $50 for effective surge
protection.
The irony is that most electricians are only technicians who know the National
Electrical Code (NEC) but don't always know electricity. The NEC is concerned with human
safety; not transistor safety. Therefore an earth ground that meets NEC requirements may
not be sufficient for surge protection.
Earth grounds must be inspected visually. There are no 'consumer priced' devices to
verify good earth ground. Those three light plug in testers do no earth ground testing.
First inspected earth ground connects the fuse box to a 10 foot copper rod just outside
the building. This ground was only recently required by the NEC, so many homes over ten
years old will not have grounds that meet recent NEC requirements.
The copper earth ground rod is connected to the fuse box by a solid (no splices) 4 AWG
copper wire that is clamped to the rod and connects to the ground bus inside the fuse box.
All screw connections must be tight. Also the rod must be firm in the ground - cannot be
shaken. That meet NEC code.
For surge protection, that 4 AWG wire should be as short as possible, definitely less
than 10 feet, and direct (minimal bends). Also any ground wire that connects to cold water
pipes must connect on the earth side of the water meter. The water pipe must have no
solder joints between where the ground wire connects and earth.
The standard Verizon surge protector must connect their green wire to this shared earth
ground rod. IOW neither earth ground wire should share a connection until they meet at the
earth ground rod. NEC required that all earth grounds have a common connection. Surge
protection requires this common connection to be at the central earth ground (ie the rod).
Another critical part of your surge protection is a ground wire to the pole
transformer. Visual inspections for continuity and firm connections must also be
inspected. If broken, then the electric company should be notified. Again, a ground to
your pole transformer is another important earth ground for your effective surge
protection.
As noted previously, Verizon already installs effective surge protection, but some
homeowners, electricians, etc. compromise Verizon's critical earth ground connection.
Visual inspection of Verizon installed green ground wire from their Network Interface
Device (a gray box) is important surge protection.
Your CATV also must be grounded to that same earth ground before it enters the building
- also for surge protection and to meet NEC requirements.
Some locations will have inferior soils - ie loose gravel or sand. In this case, the
earth ground must be expanded from the earth ground rod. Typically, commercial buildings
address this problem by encircling the building with a buried ground wire. NEC requirement
for depth, distance from the foundation, and wire size are listed (but I have long since
forgotten the numbered paragraph).
Much better surge protection is created by using $20 or $70 to expand the earth ground
- exceed NEC requirements - rather than wasting same money on plug-in surge protection. A
surge protector is only as good as its earth ground.
As noted earlier, two effective, residential 'whole house' surge protectors -
Intermatics EG240RC and Siemens QSA2020 - are less than $50 at Home Depot. Some HDs may
not have them (i.e., Exton). Ask a salesman to computer check for Qtys at other area Home
Depots.
quote:
Originally posted by wfrick:
Okay, here's what I don't understand:
How can I tell if the soil is good enough? We live atop red shale; Is that typically a
good enough conductor?
Typically not compared to clay and other soils. Visit Penn State libraries such as
Colin Bayliss's Transmission & Distribution Electrical Engineering page 225 for
examples of soils and their electrical conductivity.
how do you know the conductivity of your soil? This is the art of surge protection. You
probably don't have the best of soils, but then you don't have the worst either. Surge
protection is only as good as its earth ground. Expand your earth ground for about the
same price as an ineffective, brand name, power strip surge protector. Install a second
ground rod per the distances specified by the NEC. Just make sure that your home ground
connection and your expanded earth ground all meet at the central earth ground point.
Better earth grounds use a copper wire loop around the building and often with other
ground rods attached at different parts of the loop.
Is your soil red shale all the way down? Changes in earth can complicate the
effectiveness of earth ground. For example, if you live in Warminster with what appears to
be a very conductive bedrock underneath, then lightning may bypass your earth ground IF
lightning finds a better path to that bedrock. Again, grounding for surge protection is an
art. The best you can do is not waste money on ineffective surge protection AND to use
that money to expand you earth ground system, especially if not located in better
conductive soils.
quote:
Originally posted by wfrick:
Where would this network device be? In the house, or out on the lawn by the
curb, at the gray box?
The NID or Telephone Network Interface is where exterior grade wire meets your interior
grade phone wires. It is a gray box typically located outside the house and labeled as
above. This is also called the Premise Interface. It contains junctions for the above
wires AND a surge protector.
Older homes still have the old black bakelite surge protectors often located inside the
house. They don't use the semiconductor based surge protection that is preferred today. If
you have one of these obsolete technology surge protector (also where exterior grade wire
meets interior grade) then you should be on Verizon to upgrade. The old surge protectors
have two studs for phone wires AND a center stud for the earth ground connection. Also
what appears to be two bolt head are actually the surge protection 'carbons'.
IOW the simple answer is "Follow the wires".
quote:
Originally posted by wfrick:
Are you talking about a ground from the house to the transformer (we have no
poles, if that's what you were talking about...)?
If your utility transformer is in the ground, then you have no pole ground to inspect.
The earth ground connection is underground with the transformer. But again, visually
follow the wires. See where they go.
From PhiloLarry:
This was interesting and explains why my previous computer was fried before my eyes
when my house was struck by lightning. I now have what I think is very effective surge
protection. Here's what I do.
(1) Watch the weather channel before I leave home.
(2) If there's a threat of thunderstorms and I'm leaving I shut down my computer and
unplug everything from the wall. (Not to flame, but REMEMBER TO UNPLUG THE TELEPHONE CORD
TOO!)
That's it. Of course, it's not fool proof but I think I'm more protected than people
using the expensive systems criticized above.
Oh yes, I do have a power strip surge protector, a very cheap one that I use for the
convenience of having all those outlets on one strip. 
From Bob:
quote:
Originally posted by PhiloLarry:
If there's a threat of thunderstorms and I'm leaving I shut down my computer and unplug
everything from the wall.
Aha, the 12" air gap surge protector. 
Remember to leave the AM radio on when keyboarding. Tune it to white noise and leave
the volume down low. 
From PhiloLarry:
Ummm...I don't get it Bob. I get the air space one, just not the AM radio one...I know,
I shouldn't be allowed out of the Beginner's Forum.
From ntwrklarry:
The AM radio frequency picks up static whenever a lightning bolt does it thing and it's
within a few miles of your home. You can judge just how close it is by how loud it is on
the radio.
From barefaced:
quote:
Originally posted by ntwrklarry:
The AM radio frequency picks up static whenever a lightning bolt does it thing and
it's within a few miles of your home. You can judge just how close it is by how loud it is
on the radio.
The AM radio detects lightning because lightning is a powerful, radio frequency
electrical surge. Wire no longer becomes a conductor to lightning; wire instead becomes an
electronic component. It is why the distance of surge protector to earth ground must be so
short. Lightning is power in the AM radio band. Therefore a shorter wire is necessary to
connect to ground. The longer wire to a plug-in surge protector is all but no ground -
because lightning is a radio frequency surge - which is why it is heard on AM radios.
How far away? See a flash, then count the seconds until thunder. 5 seconds
per mile.
Unplugging for protection: there is an old story of ham radio operators who
disconnected the antenna, and had damage. They disconnected the antenna and put the
antenna wire in a mason jar; and had damage. Disconnect everything so that lightning does
not have an incoming and an outgoing path. If lightning has only an incoming path, then no
surge damage. But those ham radio operators had to discover, the hard way, how many things
really conduct electricity when that electricity is called lightning.
Concrete foundations and basement floors, reinforced in rebar, are excellent earth
ground even thought an ohms meter does not say so. Lightning is not capricious - just
misunderstood.
quote:
Originally posted by PhiloLarry:
... My computer was fried by the telephone wire, I never knew that thin little
wire could carry so much current, just didn't think about unplugging it. Now I unplug both
the computer power cord and the phone jack. So far it's worked.
If a surge entered on the phone line, then you have a phone line installation problem.
Either the line has not been upgraded in the past 15 years, or the necessary safety ground
is missing, or the surge protection is not installed. All are provided by the Telco. The
idea of surge damage: if you get it, then you are expected to learn from and correct the
problem. A surge that enters today damaging a modem will enter to damage the portable
phone tomorrow - unless the problem is corrected. |
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