, Underwriters Laboratories (UL), a global independent safety science company, defines how a protector may be used safely. They are essentially heavy-duty low-pass filters connected so that they allow 50 or 60 Hz line voltages through to the load, while blocking and diverting higher frequencies. UL 1449 became compliance mandatory in jurisdictions that adopted the NEC with the 3rd edition in September 2009 to increase safety compared to products conforming to the 2nd edition. … This Tripp Lite 10-outlet model … Keys to determining the amount of protection needed include the type and value of the equipment to be protected. It may start to short at 270 volts but not reach full short until 450 or more volts. Our Pick. TVS diodes are also used where spikes occur significantly more often than once a year, since this component will not degrade when used within its ratings. Long term surges may or may not be handled by fuses and overvoltage relays. When you buy through our links, we may get a commission. However, if the spike is large enough or long enough, like a nearby hit by lightning, there might not be enough power line or ground resistance and the MOV (or other protection element) can be destroyed and power lines melted. See "Varistor Rating Assurance Tests" on page 10-145 for definition of "end-of-lifetime. Don't use a surge protector with an aquarium or other water-associated products. It’s very easy to install. The KEY difference between the two models is how they do their intended job. If the voltage happens to rise above the acceptable level, the protector will divert the extra electricity into the outlets grounding wire. It works the same way as the panel surge protector does by stopping excess energy right at the source, before it enters your home, and diverting it out into your grounding system. A surge protector joule rating indicates how much energy it can absorb before it fails. Scaled-down versions of these devices are sometimes installed in residential service entrance electrical panels, to protect equipment in a household from similar hazards.. What Does A Surge Protector Combat? But, surge protectors also have electronics built in that help prevent power surges from damaging connected devices. Surge protectors for homes can be in power strips used inside, or a device outside at the power panel. Important Points About Surge Protectors. 4. What makes a good surge protector?  Surge Protector: A surge protector is an electrical device that is used to protect equipment against power surges and voltage spikes while blocking voltage over a safe threshold (approximately 120 V). They are cheap products … 120 vac or 240 vac. If the voltage from the outlet surges or spikes -- rises above the accepted level -- the surge protector diverts … Due to their relatively limited current capacity, TVS diodes are often restricted to circuits with smaller current spikes. Many homeowners believe that adequate surge protection begins and ends with plugging their computer into a power strip. An electrical surge protector will divert, or ground, such spikes before they can reach the protected device. Here are a few tips before you start shopping. Even tens of milliseconds can be longer than a protector can handle. Surge Protector Recalls. What does a UPS and Surge Protector do? A strong surge or lightning strike can easily take out the power brick itself, and the laptop along with it if the surge is strong enough. However, it usually has a longer life than an MOV. It can dissipate power continuously, and it retains its clamping characteristics throughout the surge event, if properly sized. It is installed in your cable box, which is usually found mounted on a wall outside your home. These are some of the most prominently featured specifications which define a surge protector for AC mains, as well as for some data communications protection applications. The typical spacing for telephone applications in North America is 0.076 mm (0.003 inches). Have you ever experienced a bursting water hose? CNET editors pick the products and services we write about. Look for surge protectors with an absorption rating of at least 600 joules. GDTs take a relatively long time to trigger, permitting a higher voltage spike to pass through before the GDT conducts significant current. (On a related note, definitely check out #10. 2). In-field installation costs can be higher, since SM devices are installed in series with the power feed, requiring the feed to be cut and reconnected. When the voltage rises above the acceptable level, the surge protector suppresses the excess voltage to prevent it from causing harm. “When a sudden increase in voltage occurs, such as from a lightning strike or damage to a power line, a surge protector detects the excess current and safely diverts it through the house’s grounding path.” A simple statement and it sounds great, but what does it mean? Some surge protectors have connectors for these as well. [clarification needed] If component ratings are exceeded, the diode may fail as a permanent short circuit; in such cases, protection may remain but normal circuit operation is terminated in the case of low-power signal lines. A surge protector is a device that shields computer and other electronic devices and appliances from surges in electrical power or a transient voltage that flows from the power supply. The cable surge protector is very similar in function to the panel surge protector. How does surge protection work? MTL TP surge protection for 2, 3 & 4 wire transmitters. This is different from other types of protectors that may attempt to absorb the surge. None of those standards guarantee that a protector will provide proper protection in a given application. A second MOV might start at 290 volts and another at 320 volts so they all can help clamp the voltage, and at full current there is a series ballast effect that improves current sharing, but stating the actual joule rating as the sum of all the individual MOVs does not accurately reflect the total clamping ability. Spikes can also occur on telephone and data lines when alternating current (AC) main lines accidentally connect to them or lightning hits them or the telephone and data lines travel near lines with a spike and the voltage is induced. For a little background, check out what makes a good surge protector. Best Surge Protector. In contrast, the IEC only writes standards and does not certify any particular product as meeting those standards. The absorption rating is how much power the surge protector can withstand in a surge. A Surge Protector is a device designed to control high-speed, high voltage transients or surges that are common in electrical systems. At this point the MOV conducts more and more often, heats up and finally fails. Here's the dirty little secret: Your gear already does this. Therefore, GDTs should be shielded from light exposure, or opaque versions that are insensitive to light should be used. If you live in an area with lots of thunderstorms, your gear is probably more likely to experience power surges. Most models also have an input for a phone line, to protect your modem from power surges, and may feature built-in circuit breakers. Shorting is done by spark gaps, discharge tubes, zener-type semiconductors, and metal-oxide varistors (MOVs), all of which begin to conduct current once a certain voltage threshold is reached, or by capacitors which inhibit a sudden change in voltage. When a threshold is over 120V, a surge protector shorts to ground voltage or blocks the voltage. The most common and effective way is the shorting method in which the electrical lines are temporarily shorted together (as by a spark gap) or clamped to a target voltage (as by a MOV) resulting in a large current flow. The strips usually have an on and off switch, but it does not offer surge protection from electrical issues. Almost nothing actually runs on 120 volts (or alternating current, for that matter), so unless you've got some really wacky (or cheap) gear, and live in an area with bizarrely inadequate power, a power conditioner isn't something you need. A surge protector which is under a rating of 1000 joules can easily protect small devices like radios, lamps, battery chargers etc., but will not be suitable for your computer or gaming consoles. A surge protector guards against the damage that sudden power surges can cause. Surge station - These large surge protectors fit under your computer or on the floor. Better protectors exceed ratings of 1,000 joules and 40,000 amperes. Past recalls have included power strips or surge protectors which turned out to be defective or faulty and may have increased the risk for a surge protector fire. Many protectors will connect to all three in pairs (line–neutral, line–ground and neutral–ground), because there are conditions, such as lightning, where both line and neutral have high voltage spikes that need to be shorted to ground. An Ethernet surge protector works much the same way, but also provides “in” and “out” sockets for Ethernet cables to be plugged into the surge protector, providing protection from surges through an Ethernet cable as well. If the pressure is greater than what the hose can handle, but not enough to burst, it will weaken and eventually erupt. NFPA's primary concern is protection from fire. A surge protector is a simple, less costly way of protecting your electronic devices from power surge. According to industry testing standards, based on IEEE and ANSI assumptions, power line surges inside a building can be up to 6,000 volts and 3,000 amperes, and deliver up to 90 joules of energy, including surges from external sources not including lightning strikes. Use surge protectors indoors and in dry locations. No. Each year in the U.S., hundreds of consumer electric devices are recalled. If you've had your current surge protector for more than a few years, it's probably worth replacing. 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