When people think of surge protectors, their first mental image is usually the typical surge protector power strip. They think it is convenient because it allows them to plug multiple components into one power outlet, which can especially be useful in high volume areas, like near a computer work station. But they also perform the essential duty of protecting your electronic devices from surges in power.

These power surges are the product of transient voltage, which is an increase in voltage significantly above the desired level of electrical flow. In the United States, most devices are wired to handle 120 volts, and when the voltage rises above this there can be a problem. These volts are measured in electric potential energy. As the electric current travels between points, there is a greater electric potential energy on one end of wire than on the other end. This is the same sort of principle that applies to water in hoses – higher pressure on one end causes the water (or, in this case, electricity) to push towards an area of lower pressure. When the increase in electrical flow lasts for longer than three nanoseconds, it is called a surge, and when it lasts one or two nanoseconds, it is caused a spike. Just like with hoses, when there is too much pressure built up within the wire, it can “burst” or burn out, causing either an immediate break in your machine or putting extra strain on the components. Surge protectors work to prevent this from occurring and your electronic items from getting damaged or destroyed. These devices divert the extra electricity from an electrical surge or spike via a metal oxide varistor, or MOV into the outlet’s grounding wire. The MOV has three parts – a piece of metal oxide material in the middle that is surrounded by two semiconductors, which have variable resistance that is dependent on voltage. When the voltage is correct, the MOV does nothing, but when it is too high it will eliminate the extra voltage.

There are other types of surge protectors, including gas discharge arrestors, which are not as common. Regardless of which type of surge protector you choose, it is important to have one to protect your important devices in your home or office.

Hazard alert systems come in a variety of instances, all of which are important. Some may alert you of fire, while others are used as burglar alarm systems. They remain passive most of the time, but when they are needed – when there is danger – it is intensely important that they work properly. Malfunctions in the system can be costly – often we only think of the costs that can incur if the system does not work when it should and damage is caused to the property, but there are also costs if the system causes a false alarm (as surveys show several hundred million dollars are spent every year on false alarm responses in industrial countries). Besides the monetary costs, false alarms can cause guards to start ignoring the alarm messages, and the operator to start questioning the significance of the system, as well as the activation of the systems causing interruption of operations.

Therefore, picking the right lightning and surge protection for your hazard alert systems is a high priority for most businesses. There are two main monitoring systems used when dealing with hazard alert systems, the first being impulse line technology, which transfers information from the triggered alarm through digital means, and allows for exact localization of the trouble spot, and d.c. line technology, which allow the alarm line to be permanently monitored by a closed-circuit, which triggers an alarm in the control and indication equipment, although not one giving the specific location of the trouble spot.

There are different recommendations when it comes to surge and lightning protection based on whether your company uses an impulse line or d.c. line technology system. Not only is surge protection of the lines important, but there should be some protection for the power supply as well, with DEHNguard modular surge protective devices as the top recommendation for this. It might also be wise to consult with the manufacturer of the alarm systems in order to determine the exact specifications for the protective systems to use. To learn more about what DEHN has to offer in terms of surge and lightning protection, you can download our chapter “Surge Protection for Hazard Alert Systems”, located in the Lightning Protection Guide.

Public Address systems, or PA systems, are used in order to transmit voice, music, and signal transmissions. They consist of some system of a mixer, amplifier and loudspeaker, but exact specifications of these can range greatly. They are often used in their most simple instances for small venues like school auditoriums, churches, and small bars. Larger instances with multiple speakers can be seen in institutional and commercial buildings, where they are used to read announcements or declare states of emergency. Intercom systems are another variation of public address systems, and are commonly seen in schools, where microphones are located in each room so occupants can reply to the central office.

Generally, the transmitters use telecommunication cables that are attached to a variety of different kinds of loudspeakers. The lowest nominal power of amplifiers is about 100 W, with the highest going up to 600 W or more, and the power used for different loudspeakers can vary greatly, as fitting the range of fitting or surface mounted loudspeakers is 6-30 W, loudspeaker columns is 20-100 W, and horns are approximately 10-60 W. Note, though, that there are many different regulations that can come into play when trying to find the right surge protection for your system – including building regulations, and specific regulations for public address emergency systems and danger alarms for cases of fire or raid – so it is important to make sure you find a system adequate to protect your needs as well as up to date with codes.

In order to learn more about the basic specifications used when dealing with surge protection with PA systems, you can download our chapter on “surge protection for public address systems” from our Lightning Protection Guide.

While Dehn generally concentrates on larger businesses, it is important that you understand the basics of surge protection. While our surge and lightning protection systems can help you in the long run, protecting your entire building from electrical issues that could end in the loss of power or data for your business, as well as repercussions with your computer systems, there are also in-house steps you can take at a smaller level to protect your company.

So why do you need to take the extra precaution of adding surge protection to your home and office computers? Simply because surge protectors can keep the little circuits inside your computer safe from excess voltage spikes, which cause the electrical circuits to heat up. A big surge, or spike, can cause the circuit to blow on the spot, while smaller surges can cause damage over a period of time, causing the system to eventually fail. Most people associate these power surges with storms, when lightning strikes the power line and causes a spike in the power, but there are many everyday occurrences that can cause power surges as well. Most of these surges are from high powered appliances, and can include refrigerators, air conditioners, furnaces, and even hair dryers and vacuums.

Another thing to note is when looking for a surge protector, try to find one that features a phone line “pass through”, as telephone wires can deliver a potent surge into the computer. In fact, phone lines are actually more likely to cause damage. Computers have some slight surge protection built into their power supply to counteract regular surges through power lines, but nothing for phone lines. A good quality surge protector can cost anywhere between $20 and $100, depending on where you go and what you are looking for. A way to find a good surge protector is to consider its “connected equipment” warranty – the more of your possessions they are willing to guarantee coverage for, the more rest assured you can be that you are purchasing a good and safe surge protector.

So take that small and easy step to help protect your computers and electronics from power surges – you’ll be thankful in the end!