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Why Surge Protection?
Until the
introduction of solid-state devices, most AC powered equipment was too
insensitive to be upset by “dirty†or surging power. However, electrical power surges and the damage they can cause are commonplace today. Our home and workplace are comprised of solid-state devices vulnerable to surges. We deal daily with computers, office machines, telecommunication equipment, data, major appliances, etc. All of these depend on solid-state devices, which are vulnerable to surges.
Solid-state devices depend on consistent, good-quality power. A single powerful surge literally melts, welds, pits, and burns its way through solid-state circuits and components.
Device failure is often the result of surges, the repairing technician may or may not detect. In
addition to the loss of use, the priceless stored data is lost and
meaningful input or output information is turned into nonsense. The
driving force to shrink device geometries to increase speed and storage
capacity will continue to make solid state devices even more sensitive
to AC power.
Many people think of surge damage as being caused by a single, catastrophic event such as a lightning strike. While lightning is one of the most powerful and destructive surges, it’s not always the cause of most of the surge damage. In reality, surges range from the mighty to the minuscule.
Smaller surges occur several times a day, or hundreds of times an hour. Almost continuous surges can be produced by sources ranging from 250 to over 1,000 volts. Typically,
they are caused by the operation of electric motors or other inductive
loads such as elevators, office machines, HVAC equipment and material
handling equipment. Microwave ovens, vacuum cleaners, lamp dimmers and countertop appliances are some of the surge sources in the home.
Powerful, random surges result from the switching of an inductive load such as
an electric motor starter, arc welder, furnace ignition, compressor, etc. and these momentary surge sources range
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from 250 to over 3,000 volts. Over
or under voltage power conditions over 250 to 6,000 volts usually
accompanies a utility switching lines to meet changes in demand, or
when correcting a brownout or blackout.
While mother
nature provides the most visible and spectacular surges in the form of
lightning, the power company, your own equipment, other equipment in
the building you occupy, or from a source some distance from your
facility can generate the sure damage you suffer. Surges
travel on AC lines, data lines, communication lines, coaxial cable,
metal fences, metal conduit, metal duct work, as well as through the
ground and air. Surges travel via any conductor they can find.
Surge damage can be classified into three categories: Hard Failures, Glitches and Latent Failures.
Hard failures cause damage requiring repair or replacement of electrical components.
Glitches usually do not cause permanent damage, just temporary damage or lost data.
Latent failures result from continuous exposure to smaller, non-catastrophic surges the erode equipment and its performance. In the end, the equipment suffers hard failure and the cause is unseen.
Noise is another problem in power lines. Conducted noise is the most destructive type. It is usually present in your AC power source and you are surrounded by these radiated noises.
Noises can come
from the most simple device, such as an electric razor or a fluorescent
lamp, cars, TV’s, cellular phones, electrical transformers, lamp
dimmers, office machines, etc. are other examples. The list is endless. To solid-state devices, this is an invisible and lightning-fast destructive force.
A high quality
surge suppression system is your first, best and only defense against
these potential threats to your equipment, data and operation.
No one can guarantee to protect you from a direct and catastrophic lightning strike.
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Even the best
lightning protection systems have their limits. A properly designed and
installed surge suppression systems can provide you the best defense
against all but the catastrophic direct lightning strike.
It is important that a surge suppression system be just that – a system, not individual units of spot protection.
In designing the system, many factors should be taken into consideration. Every facility has some equipment that is critical to the overall operation of the facility. That equipment will probably require higher levels of protection.
Equipment controlled by solid-state device is more susceptible to surge damage. Each facility is different and will require different levels of protection for perhaps even similar pieces of equipment.
The Institute of
Electrical and Electronic Engineers (IEEE) has developed a schematic
showing the levels of surge severity relative to location and showing
even the point of entry of the electrical line. If surge sensitive equipment is located on the same circuit as equipment that generates surges, it must have protection. The only way to properly design a system of protection is careful evaluation of each and every facility.
Different surge suppression units offer varying levels of protection. All
have the same basic job, to prevent damaging voltage spikes from
reaching the device it is intended to protect. More sophisticated
suppression units also filter noise.
Only a thorough
survey of your facility and it power supply, an examination of
electrical layout, circuit plans and inventory of devices (present and
future) connected to all circuits can provide the information to form a
recommended plan of protection.
High quality
surge suppression units, when properly applied in surge suppression
systems, are one of the best investments you can make. Considering the small cost, it will be hard to find a higher return on any investment.
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