by Garth Powell *
When one talks about the dangers of AC power, usually the first thing that comes to mind is the lightning. Actually, lightning is a serious threat to electronic equipment, particularly in many regions of Latin America. In fact, some equatorial regions of South America experienced the highest annual impacts rays than any other place on the planet.
Lightning can cause catastrophic moments on the voltages (shaking) to pass on wiring, wires, tubing or any other conductive material, and can be devastating for electronic equipment. Because the beam load an incredible amount of energy, there may be damage to equipment within a mile or more away from where it presented the direct impact. Even if the current of a lightning strike does not lead directly to a site, the electronics can be damaged by a nearby impact because the wires pick up the electromagnetic field generated when the impact occurs.
A system of structural lightning protection installed properly composed arrestor rod and conductors ranging from the grounding system of the building will protect the building itself; however, they are electronic therein remain at risk. A guard at the service panel can be an effective first line of defense, but because many shocks can occur within a building (after the panel), protection must be used at the point of use at each site where they are the teams. Such protection should cover not only the AC lines but also any coaxial or telephone line, since harmful jolt can pass through the signal lines as easily as they do power lines. Technology in the most advanced management components current energy can protect against almost anything, besides a direct lightning strike on the incoming line or the service panel (thank goodness this is an event that happens very rarely).
However, the dangers of AC power for any reason are limited to the impacts of lightning. The energy infrastructure AC was built over 100 years ago, and although the technology in our equipment has evolved, the basic system to power the equipment remains obsolete, outdated and in many areas has poorly maintained and has many problems.
For example, in many parts of Latin America, the transmission of AC power that is consistent (ie, constant energy, without blackouts) or not present voltages to fluctuate dramatically in the day or during the week (voltage constant AC - regulation ) is very rare, unfortunately. Users generally are forced to resort to industrial voltage regulators rudimentary at dieses generators, gas or ferro-resonant devices AC just to maintain basic services. In addition to this, it is the fact that most of its sensitive electronic components were created for an average of 120VAC (not 127 normally found in many areas such as Mexico) or 220V-240V, and at most only accounts with a booklet annotations to operate deficiently electronic circuits, and to make matters worse they have a limited life and the continuing need for reloading or repair.
Given this, the best that can be expected for some challenging installations is to use what you have on hand in order to keep the equipment running. However, the device management AC power that is suitable for lighting or electric cooling is perhaps not appropriate for sensitive current microprocessors circuits (ie, computers, server systems, automation, processors audio-video, projectors and safety equipment).
For example, the active devices yesterday (such as tubes and transistors vacuum) could handle large pulses of temporary voltage without any problems, while current circuit boards densely packed and critical microprocessors are highly susceptible to arcing voltage. Three volts are sufficient to cause permanent damage to many connections.
By design, services or local power substation countless impulses sent through a weekly AC wiring. In fact, they could be among dozens and hundreds of pulses daily. This is due to necessary changes of a transformer (or supply subsestación) to another during the day, thereby adjusting the high demands. This hidden danger is the cause of many seemingly inexplicable problems and many erratic in today's electronic behavior, and without proper protection problems will manifest themselves more frequently with the passage of time (greater digital errors, data loss and distortion , just to name a few).
In addition to the temporary impulses, another substantial danger to equipment are sustained overvoltage conditions. The sustained surge can be caused by many reasons: failure of wiring in an electrical system of a building can lead to the loss of a neutral line, a storm or an accident can cause a power line high voltage has contact with a line low voltage distribution, or malfunction in energy services that may cause a catastrophic overvoltage condition, with consequent immediate destruction of the computers that are connected unprotected. Many savers energy impulses and tapes offer no protection against these conditions and, in fact, may involve a risk of fire. To properly protect a sustained surge, make sure your device power management circuit have an extreme voltage shutdown constantly monitor the incoming voltage and disconnect the power instantly when there is an external nominal range.
Finally, it should be noted that the electronic equipment is designed to work with power 120V or 220V-240V, depending on the country where we live. Always load a voltmeter and check the incoming voltage at each installation site before specifying the equipment. Although each energy service will endeavor to provide a nominal voltage, load conditions, the resistance of lines or poor regulation in the main transformers can cause supply voltages above the nominal given range. In this situation, a voltage regulator must be installed.
For installations A / V, seek a regulator that provides solid state switch to eliminate noise while regulation is performed. This ensures that sensitive components that require high current regulation and low noise work optimally.
There are clearly many considerations that must be taken into account in relation to AC power and how to offer the best way to customers high performance and investment protection. In future articles, we will look into problems such as unstable voltages and noise from the AC line, and how to solve them in the best way.
*Garth Powell is the Senior Product Designer and Senior Sales Engineer Furman, a world leading provider of energy management solutions. It can be contacted at: firstname.lastname@example.org.