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How to Choose Surge Protection for Your Home
Here are some shopping tips to use when purchasing
your surge protection system...
Service Entrance Surge Protection
Service entrance surge protection devices will
either be a TVSS or a secondary surge arrester. It
is not possible to compare the capabilities of a
TVSS to a secondary surge arrester because they
are tested differently. State Farm is not
recommending one type over another. We will offer
suggested specs for both.
- Tested Product: It is very
important that the device has been tested.
Look for a secondary surge arrester that is
tested according to the recommendations of
IEEE C62.11 or a TVSS that has been tested
in accordance with UL 1449, 2nd Edition.
- Fuse Protection: Look for a TVSS
device that has thermal fuse protection. If
the device is a secondary surge arrester,
make sure it is fused.
- Clamping Voltage (Rating): TVSS
service entrance surge protectors will
typically have a clamping voltage higher
than 330 volts.
We do not currently have a recommendation
for a minimum clamping voltage for TVSS
service entrance surge protectors. For
information purposes only, it appears most
of the established manufacturers of these
devices have a clamping voltage no higher
than 800 volts.
The lower the clamping voltage the better
Service entrance surge protection devices
classified as secondary surge arresters will
not have a clamping voltage because they are
not tested to UL 1449. Purchase a device
that is tested according to the
recommendations of IEEE C62.11. Talk with
the manufacturer about the device's
capabilities. Since there is no standardized
test method for secondary surge arresters,
each manufacturer may test their product
differently, making a performance comparison
between products difficult or impossible.
- Surge Protection on All Electrical
Wires: Verify the surge protection is on
all electrical wires. TVSS devices should
indicate protection for Line to Neutral
(L-N), Line to Ground (L-G), and Neutral to
Ground (N-G). Secondary surge arresters
mounted on the utility side of the
electrical panel will have only L-N
- Telephone and Cable TV Protection:
Install surge protection on the incoming
telephone and cable TV lines as well as the
electrical line. It is possible to
accomplish this with one surge protection
device or separate surge protection devices
at each utility line.
- Working Indicator Light: Most all
service entrance surge protection devices
have indicator lights that will signify if
there are any problems with the protection.
Be sure the device you buy has this feature.
Most of these devices, if the surge
protection capabilities are destroyed, will
still conduct electricity. The indicator
lights are a way to check to make sure the
device is still protecting.
- Good Warranty: Find an
established manufacturer with a good
reputation. Their warranty should cover any
damage to the equipment that is protected by
- Joule Rating: The joule rating
indicates how much energy a surge protection
device can handle. Because testing to
determine joule ratings has not yet been
standardized, the joule rating cannot
currently be used for comparing products.
Point-of-Use Surge Protectors
- Tested Product: These types of
surge protectors all fall under the
category of TVSS. Purchase only devices
that have been tested to UL 1449, 2nd
- Thermal Fuse Protection: Look
for a device that has thermal fuse
- Clamping Voltage (Rating):
Purchase TVSSs with a listed clamping
voltage of 330-volts, the best rating
given under UL 1449. It will not be
difficult to find TVSSs that plug into
outlets and have a clamping voltage of
330-volts. However, we could not find
surge protection outlets with clamping
voltages less than 400-volts.
The clamping voltage can be found on the
surge protector's rating plate (see
Surge Protection on All Electrical
Wires: Make sure the surge
protection is on all electrical wires.
The device should indicate protection
for Line to Neutral (L-N), Line to
Ground (L-G), and Neutral to Ground
(N-G). A clamping voltage of 330-volts
should be listed for all three wires.
Fax/Modem and Coax Protection:
When purchasing a point-of-use type
surge protector for a computer, VCR,
or TV, look for a device with
telephone and coax cable jacks for
protection of those lines if the item
being protected has those types of
hookups. Remember, power surges can
enter through the electrical,
telephone, or coax lines.
Loss of Power After Catastrophic
Failure Feature: Look for
point-of-use surge protection devices
that no longer conduct electricity
once the capacity to protect against
power surges has been lost.
Surge protection devices are designed
to sacrifice themselves for the
equipment they are used to protect.
Once they have had too many surges,
they no longer protect. However, if
they still conduct electricity, a
homeowner may never be aware the
device has lost its ability to
protect. With this feature, once the
protection has been destroyed by a
power surge, the surge protector
outlets will no longer be powered.
Ground Wire Indicator Light: A
convenient feature to have is a
plug-in type surge protector that has
a light that will indicate whether or
not the outlet it is being plugged
into is properly grounded. Grounding
is required for the surge protection
device to work most effectively.
Good Warranty: Find an
established manufacturer with a good
reputation. Their warranty should
cover any damage to the equipment that
is connected through their surge
Joule Rating: The joule rating
indicates how much energy a surge
protection device can handle. Because
testing to determine joule ratings has
not yet been standardized, the joule
rating cannot currently be used for
Surge Protectors must be properly grounded
Without proper grounding a surge protection
device's ability to protect is greatly diminished
or impeded. Do not connect a plug-in type point-of-use
surge protection device to an electrical outlet by
using a two-prong extension cord. The surge
protection device's ability to protect against
power surges will be diminished. And many surge
protection device warranties will not cover any
damage if this is done.
Planning of Electrical Circuits
If you are building a new home or remodeling,
properly organizing the electrical circuits can
reduce exposure of power surges to sensitive
equipment. Don't place wall outlets that are going
to be used for computers, TVs, microwaves, and
stereos on the same circuits powering large
appliances with motors, such as refrigerators or
Costs of surge protection
Service entrance surge protection at the main
electrical panel or electric meter requires
installation by a qualified electrician.
Installing it at the electric meter also requires
the approval of the utility company. Service
entrance surge protection (for the electrical
system only) can also be accomplished with plug-on
devices that snap into the electrical panel just
like a circuit breaker.
Costs for service entrance surge protection can
start at $80 (material and labor) for the plug-on
type devices inside the electrical panel. For
those mounted on the outside of the main
electrical panel or installed at the electrical
meter, the range is $150 to $500 (material and
Costs can range from $20 to over $100 for better
quality point-of-use type surge protection devices
that plug into electrical outlets.
Surge protection outlets, which require the
services of a qualified electrician, cost around
$40 (material only) as compared with a typical
electrical outlet that costs around $2 to $4
Why hasn't damage from power surges been a problem
before now? Power surges have always existed.
Appliances and products going into our homes,
however, have changed.
Sensitive electronic circuitry is appearing in
more and more appliances in the typical American
home. Also, the amount of electronic equipment in
the home is increasing -- DVD players, satellite
TV, video games, stereo systems, and personal
computers are becoming commonplace.
The electronic circuitry is getting more dense and
compact, making the circuitry more vulnerable to
damage from power surges. Equipment and appliances
are becoming more interconnected with one another
and more connections will be made with phone lines
and coax cable lines. Electric utility companies
are deregulating at a time when there will be more
demand for electrical power. All this increases
the chances of damage from power surges.
The cost and number of electronics and smart
appliances in the home will continue to increase.
Combining this with the potential increase in
power surges means damage from power surges will
cost us more in the future.
The cost is not borne solely by insurance
companies. The consumer loses also. Most power
surges do not originate from lightning strikes.
Damage from power surges created by the utility
company or generated within the home is either not
covered or has coverage limitations in most
Even for damage caused by lightning, coverage is
often limited (depending on type of insurance
coverage) because of the depreciation on the piece
of equipment and the deductible. Because of the
potential financial loss to the homeowner, a good
surge protection plan should be considered, no
matter where you live in the country.
Understanding the problem and knowing what options
are available to you puts you ahead in the
protection of your property.
State Farm® believes the information
contained in this article is reliable and accurate.
We cannot, however, guarantee the performance of all items demonstrated
or described in all situations. Always consult an experienced
contractor or other expert to determine the best application
of these ideas or products in your home.
Thanks to our friends at
Farm Insurance from allowing us to reprint this article.
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