What is the difference between a surge protector and an extension cord? Surge filter - overview of models

With the development of technology, the number of useful devices is growing, without which it is already difficult to imagine our life. Today, all household appliances and gadgets need to be connected to an electrical outlet for constant operation or recharging, so the need for a large number of sockets is constantly growing. Surge filters are equipped with short circuit protection, individual or general switches. In addition, advanced and expensive models filter high-frequency interference, which is formed due to a large number of devices connected to the electrical network and poor, old wiring.

How it works?

The surge protector, depending on the cost, performs the following functions:
1. Short circuit protection;
2. Filtering high-frequency interference;
3. Protection against short-term voltage pulses.

Short circuit is a condition of an electrical circuit when phase and neutral are connected directly without load. Those. if a wire breaks somewhere, if something short-circuits in some device, then the surge protector should turn off and protect the remaining equipment.

Interference is a consequence of the operation of devices connected to the network. Almost all electronics now use switching power supplies - TVs, computers, etc. Switching power supplies inevitably interfere with the network. In addition to them, devices with inductive loads, such as a refrigerator, also cause interference.
High-frequency interference does not harm electronics, but it does affect its operation. For example, extraneous sounds may appear in audio equipment, or ripples and distortions may appear on the screen of an analog TV or monitor.

Voltage pulses arise due to the connection of any reactive load to the network, again a refrigerator, welding machines, etc. To prevent anything from accidentally burning out, varistors are installed in surge protectors that absorb these impulses. But they rarely protect against prolonged exposure to high voltage.

Types of network filters

Extension- the simplest device consisting of a wire and sockets. It does not have filters or circuit breakers to prevent short circuits.
Network filter- the same as an extension cord, but with a high-pass filter, i.e. Eliminates high frequency interference. In addition to this with a switch and often with a thermal breaker.
Tee , splitter– a regular splitter for several sockets without a wire.
Wattmeter– a measuring device that determines the power consumption of electricity.
Energy meter– similar in principle to a wattmeter; in addition, it records power consumption in a similar way to a meter.

Number and type of sockets

Modern surge protectors have up to eight outlets. Consequently, you can connect up to eight network devices to one wall socket through a filter - this is a definite plus. But it is worth considering: connecting a large number of devices to the filter can lead to its automatic shutdown due to overload.

There are many different types of connectors; in surge protectors there are two types of sockets:
- Type C And type F. European type socket, two round pins. The difference between type F is that it has contact plates for grounding, which type C does not. Grounding the outlet allows you to avoid unpleasant and sometimes dangerous situations. Many have encountered the problem of electric shock when touching a washing machine or electric stove; this occurs due to a lack of grounding. In most apartments, grounding is done only at the stove.

Manufacturers produce filters with a plug IEC C14(computer). This type of connector is used for direct connection to an uninterruptible power supply. A surge protector connected directly through the UPS helps to more reliably protect equipment from power surges and power outages.

Basic parameters of network filters

When choosing a surge protector, you should pay attention to maximum power of the connected load And maximum load current. These parameters allow you to calculate the feasibility of purchasing various models. When calculating the maximum power, the current must be multiplied by the voltage (for example: 5 A multiplied by 220 V and we get 1100 W). Then we add up the power of the devices that are planned to be connected through the surge protector. If the total power of the equipment is higher than the maximum permissible power of the filter, then you should select a model that can withstand a higher load.
For example: when connecting a PC and peripherals to a surge protector, it will work flawlessly, since the power consumption of these devices is low. But if you plan to use a surge protector in the kitchen and connect an electric kettle, stove, and water heater at the same time, then if all appliances are operating simultaneously, the filter will turn off.

Levels of protection

According to the degree of protection, network filters can be divided into:
1. Basic level of protection (Essential). Such filters have the simplest (basic) protection. During voltage impulses, they take the blow and are characterized by low cost and simplicity in design. It is better to use them with inexpensive and low-power equipment. Serve as an alternative to conventional extension cords.
2. Advanced level of protection (Home/Office). Suitable for most appliances in the home and office, they are presented on the market with a wide range of products and loyal prices in relation to quality.
3. Professional level of protection (Performance). Eliminates almost all interference, recommended for purchase for expensive interference-sensitive equipment. Surge filters with a professional level of protection are more expensive than the previous ones, but their reliability fully pays for the costs.

Protection against short-term voltage surges/pulses– almost all filters are equipped with this function; the principle of its operation is to absorb short-term high-voltage pulses. It does not protect against prolonged high voltage. If your home has high or low voltage most of the time, then it is better to give preference to a stabilizer, since the surge protector will be useless.
Overheat shutdown- the overheat sensor is responsible for shutdown; when the temperature rises above the maximum permissible limit, the network filter is de-energized. When using the filter near heating appliances or at maximum power consumption, an overheat sensor will help avoid its breakdown or dangerous situations.
Interference suppression- in Russia, the power supply frequency is 50 Hz, but there are also additional high-frequency harmonics in the network. The filter eliminates high-frequency “dirt” and reduces it to a minimum, thereby leaving a pure 50 Hz sine wave without unnecessary harmonics.

Switch

Surge protectors are equipped with a switch so that you do not constantly pull the plug out of the socket; the switch saves time and is safe to use.
There are several types of switches:
Individual– installed for each surge protector socket, there is no need to remove a specific device from the filter, you can simply press a button.
Are common– installed on the top or side of the filter, de-energizes all devices connected to the surge protector.
Remote controls– models of surge protectors with a remote control are rare, their price is high, but you have to pay for convenience. Easy to use, suitable for people with disabilities.

Length of cable

A long cable provides mobility and increases the area where the connected device can be used. Long cables are convenient in rooms with a large area for construction tools, vacuum cleaners and other portable equipment. But in small rooms there is no need to take an extension cord “with a reserve”; it is enough to limit yourself to models with an average cable length, otherwise it will interfere and get tangled. The most common lengths of network filters are:

In our technological world, we are literally surrounded on all sides by various equipment and electrical appliances. We connect some devices regularly, such as mobile gadgets and computers, while others we use from time to time: vacuum cleaners, washing machines and power tools.

Almost all electronics, due to their complexity and subtlety, require a stable voltage. The most practical options for maintaining this can be stabilizers and This point is especially important for computer equipment, where at least three or four sockets are needed per workstation: a system unit, a monitor, speakers and a printer.

The best surge protectors for household appliances are able to “digest” and filter the received electricity and correctly distribute it among the devices, thereby protecting them from overload and breakdown. The presence of such stabilizers is especially important if your apartment or house has frequent power surges.

So, let's try to figure out how to choose the right surge protector for household appliances and what to pay attention to first so as not to waste your money. Let's look at the manufacturers of this equipment and give specific examples of the most successful models.

Manufacturers

In order to determine which surge protector for household appliances is better, let’s first talk to the manufacturers. Almost all countries produce equipment of this type, and Russia is no exception. Moreover, sometimes you can find quite high-quality domestic devices that are in no way inferior in their characteristics to their foreign analogues.

Supporting Russian manufacturers is patriotic and good, but if you need the best surge protectors for your home with enhanced protective functions and some additional features, then it’s better to pay attention to foreign models. Although domestic companies produce relatively high-quality products, in “difficult” cases it is better to look the other way (at least for now).

Manufacturers of the best surge protectors for household appliances:

• "LeGrand".
• PS Audio.
• SVEN
• Defender.
• PowerCube.

In our country, budget options are the most popular. Therefore, premium products from the venerable French company Legrand or the American PS Audio are not so in demand among domestic buyers. However, if you take any option from these brands, you definitely won’t go wrong when you get a truly high-quality option. Such devices are purchased for large private houses or offices, and for ordinary apartments they take cheaper and simpler ones.

The best products

In order to at least somehow get your bearings in all the diversity that is presented on the electrical appliances market, we will give specific examples of filter models. All devices from the list below can be found in specialized stores both offline and online. Therefore, there should be no problems with the purchase.

1. PS Audio Dectet Power Center.
2. APC Essential SurgeArrest PM6-RS.
3. SVEN Platinum.
4. PowerCube PC-LG5-R-30.
5. APC P43B-RS.

Let's take a closer look at all the participants.

APC P43B-RS

This is a fairly modest filter for household appliances for four plugs and with a meter cable. Users of large apartments did not fail to mention the last point in their reviews, because a meter-long wire is clearly not enough for large rooms.

The rest of the device's characteristics are fine. The total power of connected devices ranges from 2500 W, which is very good for its price category. In addition, due to the simple network filter circuit for household appliances, the reliability of the design is noticeably higher than other more complex analogues.

The model is also quite suitable for computer equipment. The presence of an active switch and fuses allows you to safely connect the system unit, monitor and other peripherals.

Advantages of the model:

• presence of fuses;
• 2500 W load;
• minimum current - 10 A;
• reliability of design;
• bimetallic circuit breaker;
• protective blinders are installed in the slots for the plugs;
• democratic price tag.

Flaws:

• cable is too short;
• four outlets are not enough for serious home systems.

Estimated cost is about 900 rubles.

PowerCube PC-LG5-R-30(20/10)

One of the most notable features of this surge protector for home appliances is the 30-meter cable. Such a long cord forced the designers to additionally equip their device with a reel that is almost twice the size of the filter itself.

The model is perfect for private houses and large apartments with rare and distant sockets. If you are planning a renovation or an outdoor party, then this surge protector for household appliances will come in handy.

The model also has enough load reserve - 3500 W, so you can connect serious devices to the outlet. Naturally, we are not talking about a welding machine, but a hammer drill, a circular saw, as well as a powerful audio center will work without problems.

Distinctive features of the model

The fly in the ointment here is the lack of good protection. Users in their reviews often complained about this point: there are no protective curtains on the fork receivers or at least some fuses. Therefore, for computer equipment it is better to look at another option. Well, the only downside is the cost of a surge protector for household appliances. Even the simplest extension cords with the same cord length are sometimes more expensive than our model.

Pros of the filter:

• long 30-meter cord;
• maximum current - 15 A;
• five receivers;
• convenient cable reel;
• low price.

• there are no fuses or curtains for the forks;
• decent weight - 2.5 kg.

Approximate price - about 1100 rubles.

SVEN Platinum

This is a relatively inexpensive surge protector for household appliances with five plugs. The main distinguishing feature of the model is the presence of separate switches for each outlet. The filter also features smart curtains for the plugs: they do not interfere at all when connecting and tightly close the compartment when not in use.

The model is designed for a maximum power of 2200 W and a current load of no more than 10 A. The presence of competent fuse blocks allows you to safely connect a computer and related peripherals. A two-meter cable length should be enough for an average apartment, so there should be no problems with connection.

Model features

In order to reduce the cost, the company had to abandon the total quality check of its products from distributors, so you need to carefully inspect the device before purchasing. Many users in their reviews have repeatedly complained about non-working switches or a falling out cord. The problem can be solved by a simple replacement under warranty in the store, but it still adds unpleasant hassle. So keep this point in mind before choosing a surge protector from SVEN.

Advantages of the model:

• five sockets;
• availability of good overload protection;
• separate switch for each socket;
• more than affordable price tag.

Flaws:

• Often there is a marriage.

Estimated cost is about 500 rubles.

APC Essential SurgeArrest PM6-RS

A good option for those who lack outlets. Although the device looks somewhat bulky, the design feature does not allow it to “roll” on the floor, and at a computer desk or TV stand, appearance is not particularly important.

One part of the sockets is on the top of the device, and the other is on the end. The model is equipped with one general switch, a pair of USB interfaces and LEDs. The latter will tell you about the state of protection, network overloads and the presence of grounding. By the way, using USB ports you can easily charge your mobile gadgets: the total current of the two outputs is 2.4 A.

Distinctive features of the filter

A two-meter cable should be enough for a computer with peripherals or a TV center. Although the filter looks impressive, users in their reviews complain that the power threshold is too low - 2300 W (not enough for serious equipment). But as an excuse, we can say that the device copes well with pulse overloads; you don’t have to worry about a separate voltage stabilizer.

Pros of the model:

• the filter eliminates electromagnetic and radio frequency interference;
• six fork receptacles;
• protective curtains;
• presence of working indication;
• a pair of USB interfaces;
• excellent network voltage stabilization;
• non-flammable body materials;
• good set of fuses.

• price;
• unsightly dimensions.

Approximate price - about 2000 rubles.

PS Audio Dectet Power Center

This is a whole complex designed for those who experience an acute shortage of sockets, as well as those who have a large amount of equipment for one room. The model can accommodate up to 10 forks. Inside the housing there are powerful filters for common mode and differential noise.

The existing set will be appreciated by recording studios and simple audiophiles, that is, those for whom the absence of the above-mentioned interference is extremely important. In addition, the filter copes well with ordinary impulses and stabilizes high or low voltage, thereby protecting the connected equipment.

Equipment Features

The sockets are technically and visually divided into three isolated areas, which allows you to work with particularly finicky devices: high-level current, digital or analogue equipment. Using this filter, you can safely and without unnecessary fears power any powerful AV system, not to mention other household appliances.

As for the reviews, the owners are completely satisfied with the device. Some complain about the too high price and decent weight, but excellent quality has never been distinguished by low prices, and as for the weight, this thing doesn’t seem to be for a briefcase or backpack - set it, connect it and forget it.

Advantages of the model:

• 10 fork receivers;
• separate zones for digital and analogue equipment;
• excellent protection system against all types of interference and overloads;
• high-quality assembly without any complaints;
• detachable cable;
• compliance with standard

Flaws:

• decent weight - almost five kilograms;
• very high price.

The estimated cost is about 35,000 rubles.

Summarizing

When choosing equipment of this type, you must, first of all, take into account the needs of your equipment and the specifics of the room. If you have a small room with a computer and no unnecessary peripherals, then a simple APC P43B-RS will be enough for you.

Do you have a house with a large area and few outlets? The PowerCube PC-LG5-R-30 will come in handy. Moreover, a convenient reel will allow you not just to connect permanently, but to move with it throughout the house. The model from SVEN will look great in the kitchen, where there are many different types of appliances and separate switches are very useful.

As a universal option, we can recommend the APC Essential SurgeArrest PM6-RS filter. In addition to the fact that it copes well with any home appliance, it also has two USB interfaces, which can significantly expand the scope of application of the device. It is also worth noting the exceptional safety of the device. As they say, it does not sink in water and does not burn in fire. Yes, it cannot cope with serious power, but in most apartments they are not needed.

If you have big demands, as well as an abundance of powerful equipment around the house, then a device from PS Audio will never let you down. It can handle everything you turn on, from a simple phone charger to a welding machine. Of course, such solutions have one very significant disadvantage - the price, but it’s also worth thinking about your equipment here. Its cost is much higher than a surge protector, and repairing a breakdown will cost a tidy sum. So in this case, saving is inappropriate and can even harm your expensive equipment.

In general, you need to approach the choice of a surge protector wisely. You shouldn’t go to extremes by purchasing an adapter from the premium segment for an average computer, but buying frankly cheap models from little-known companies is more expensive.

The stability of the current electrical network leaves much to be desired. Due to wear and tear of equipment at substations, poor quality electrical wiring, and frequent switching on of household appliances that consume high power, voltage drops are common.

Soviet-era technology was much more resistant to this than modern technology. Nowadays, its design often contains complex electronics with high sensitivity.

To ensure its stable operation, it is recommended to use surge protectors. This article will tell you what they are, how they operate, what types there are, and how to choose the right model for you.

Design and principle of operation

In appearance, it is practically no different from a regular extension cord. You can verify this by looking at photos of surge protectors. The main feature is the presence of a stabilizing unit and one or more switches. If any interference or surges occur in the network in this block, they are smoothed out.

A special circuit absorbs excess voltage and normalizes the current frequency. In the event of a sudden surge, the fuse trips, stopping the flow of electricity. This prevents damage to equipment connected to the filter.

Let's consider a surge protector device. Its circuit contains varistors, a balancing choke, a thermal fuse and inductors with cores. The latter are used to suppress high frequency interference. Their operating principle is based on the ability to sharply increase resistance when a current with a short sinusoid period passes through them.

Inductors are installed on the neutral and phase conductors. Low-frequency interference is suppressed either by its active resistance or by individual resistors, also located in series with the load.

A varistor is required to suppress short-term impulse noise. At low voltage it has enormous resistance and therefore does not allow electricity to pass through.

If the voltage rises to a certain value, the resistance of the varistor begins to decrease. Connected in parallel in the circuit, it takes on part of the load while its increased impact lasts.

Filters labeled LC are considered the most effective. Their circuit contains a capacitor with a capacity of up to 1 μF with a rated voltage equal to twice the mains voltage. This is done to make it possible to take into account any difference.

What varieties are there?

Depending on the level of security provided, network filters are divided into the following types:

Essential. Provides basic security capabilities. Suitable for simple household appliances.

Home/Office. Universal devices with an optimal combination of price and quality. Can be used with most household appliances.

Performance. Professional equipment for complex electronic devices that are extremely sensitive to the slightest changes. Provides maximum protection, but is much more expensive.

The difference between the presented types can be assessed, for example, by the ability to smooth out bursts of energy. If for a regular filter it does not exceed 960 J, then for a professional one it is 2500 and higher.

However, you must remember that the characteristics stated in the instructions for the selected model will only be achieved when used in sockets with grounding. In networks where it is not provided, the efficiency of these devices is somewhat reduced.

To choose the right surge protector, pay attention to the following:

The ratio of the number of sockets and the ability to withstand high loads. Cheap devices may be able to connect many devices, but are not designed for them at all. It is necessary to plan in advance what will be connected to this filter, sum up the power and compare it with that indicated in the technical data sheet.

It is advisable to have a small margin - about a third of the rated load. In this case, the filter will work smoothly and reliably.

Distance between sockets. It should be large enough to accommodate any adapter.

Length of cable. Choose one sufficient for comfortable use. Too long here is also undesirable - the efficiency of the device will decrease.

Plug contacts. In models from bona fide manufacturers, they are made of high-quality non-ferrous metal. This is checked using a magnet. Cheap metal will often overheat, which can damage the case and burn the contacts.

Number of switches on the surge protector. It can be in a single copy or separate for each outlet. In the second case, the advantage is the ability to control the power supply to each individual device.

And of course, remember that even the best filter will not help during a power outage. To protect equipment from this, this device must be combined with an uninterruptible power supply UPS.

Review of popular models

Let's look at the best surge protectors offered by manufacturers. The first of them is Buro BU-SP5 USB 2A-W. It has an organic appearance, takes up little space, and is relatively inexpensive. The average cost is 790 rubles. The case is white, equipped with 6 European sockets and 2 USB ports that allow you to charge mobile devices. The wire is 5 meters long, the maximum power is no more than 2.2 kW.

The ideal filter for connecting a computer is Pilot X-PRO. The length of the wire, depending on the model, varies from 1.8 to 7 meters. There are 5 euro sockets and one old style. It has an original appearance, reminiscent of a spacecraft in the best traditions of science fiction.

A special advantage is the presence of the Master Control function, which allows you to supply voltage to other consumers after turning on the main one. For example, a modem, printer and monitor can only turn on after the system unit starts. The average price is 1980 rubles.

The APC PMF83VT-RS is perfect for an LCD TV. Has connectors for connecting television and telephone cables. Provides faster data transfer rates while effectively suppressing RF noise and electromagnetic interference.

8 sockets are located at a distance from each other, which allows you to connect any power supply. Cord length – 3 meters. Equipped with light indicators indicating the absence of protection. Price – 3630 rubles.

A properly selected surge protector will significantly extend the life of often expensive household appliances. You shouldn’t skimp on this - it’s better to pay now than to incur much higher repair costs later.

Photos of network filters

Updated: 02/12/2018 16:39:25

A properly selected surge protector can protect your computer—or home appliances—from damage caused by power outages.

How to choose a surge protector for your computer: what to look for?

When choosing a surge protector for your computer, you should pay attention to the following characteristics of the device:

Type (surge protector or just an extension cord);

Number of output sockets;

Availability of separate switches for each socket;

UPS compatible;

Availability of USB connectors;

Maximum current and load power.

Moreover, the last parameter is of predominant importance when it comes to connecting expensive high-power equipment, such as gaming computers or 4K monitors.

Surge filter or just an extension cord

Today there are two types of devices on the market that, in a very general approximation, perform the same function of increasing the number of outlets - extension cords and surge protectors.

Extension Cords- very simple devices from a design point of view. They are simply additional outlets without any additional protection. But extension cords have a low price. Such devices are suitable for connecting not very powerful and inexpensive equipment, since they do not provide short circuit protection.

Network filters in essence - extension cords, which are complemented by a varistor. This functional element is designed to protect connected equipment from voltage surges, short circuits and other power problems. They are suitable for connecting high-power, expensive or current-sensitive equipment. An important feature of a varistor is the protection of both “internal” and “external” circuits. Thus, a short circuit in the external circuit will not damage the equipment connected to the filter, and vice versa.

It is worth remembering that a varistor is a “disposable” device. After a short circuit or other circuit defect that leads to its breakdown, you will need to buy a new surge protector. But it costs less than a new PC or monitor.

If you plan to use the equipment in circuits with regular voltage surges, then even a surge protector will not work. A stabilizer must be used.

Number of output sockets

This is a subjective rather than an objective parameter. However, when choosing a surge protector, you should consider the number of devices connected to it.

Three is the minimum number of sockets that is advisable to use. One of them will be occupied by the system unit, the second by the monitor, and the third can be used to connect an MFP or printer, speakers or router.

If there are many devices in the house that require a power connection (as in the example above), it is worth using filters with a large number of outlets - from five to eight.

It is strongly not recommended to connect an extension cord, splitter or tee to the surge protector. This leads to a significant increase in the load on the varistor due to the addition of additional resistance to the internal circuit.

Separate switches for each outlet

This parameter determines the ease of use of the surge protector, especially if it is connected to a stabilizer or uninterruptible power supply. Separate switches allow you to turn off a specific outlet - while current will be supplied to the others.

At the same time, surge protectors with this function are not very common. Therefore, if there is a choice between, for example, maximum power and separate switches, it is definitely worth purchasing a model with maximum power.

UPS Compatible

Many UPSs are equipped with a three-pin socket. The additional “pin” is designed to protect the connected equipment from power defects that occur when switching the current source.

Similarly, UPS-compatible surge protectors are equipped with a three-pin plug. They are recommended (but not required) for use with uninterruptible power supplies.

Availability of USB connectors

USB connectors are designed for connecting and charging various mobile devices - smartphones, tablets, players, etc. However, their presence or absence does not in any way determine the functionality of the surge protector. It just might be more convenient to charge your smartphone with built-in USB connectors.

When choosing a surge protector with built-in USB, you should take into account the charging current. So, if it is 1A, it will be suitable for all mobile devices. Charging at 2 A is intended for tablets and some modern smartphones, but on older devices it can damage the battery.

Maximum current and load power

Electrical parameters are very important if you want to purchase a surge protector that will specifically protect your computer and peripheral equipment from circuit breakdowns. And in this case, it is necessary to calculate the load that will be connected to it.

The load is calculated by summing the power of the connected equipment - the system unit (determined through the power of the power supply), monitor and other equipment. It is advisable that the surge protector be designed for a little more power than the received one - then it will be possible to include other devices in it.

The load current (in A) is calculated in the same way.

Manufacturers

Among the manufacturers of network filters, we can highlight the companies Sven, Pilot and ERA. The former produce various computer accessories. Their surge protectors are low priced and have good reliability.

Pilot is one of the most famous manufacturers of surge protectors. His solutions are the most technologically advanced.

"ERA" produces, perhaps, some of the most reliable network filters.

But solutions from Pilot and ERA are quite expensive.

Attention! This material is the subjective opinion of the authors of the project and is not a guide to purchase.

Some devices are connected to the network through their own transformers, which lower the network voltage to the required value for the operation of the device voltage, but often household appliances are connected directly to the network. There is a risk of expensive home equipment failing due to a sudden power surge. Using a surge protector will prevent your equipment from being damaged due to power surges.

Purpose

Surge filters are presented on the market by various manufacturers of electrical products. The purpose of this device is to keep in working order devices and equipment powered by electricity during a possible power surge. A surge filter is a device that protects devices from power surges in the network; it looks similar to a simple extension cord, but a special unit can filter out interference and extraneous vibrations that are harmful to electronic devices.

Surge filter - what is it, what is it for? Each household appliance has a passport, which contains requirements for the network from which it will receive electrical energy, in the Russian Federation this is a frequency of 50 hertz and the voltage necessary for the operation of the device or household equipment. What happens in practice:

• in every house there are residents who carry out repair work, use a welding unit or other electrical tools;
• there is a possibility of including some kind of production workshop in your line.

This is what leads to a failure in the supply of high-quality electricity to the consumer from the substation, which affects sensitive office equipment, as well as modern household appliances and televisions.

The normal operation of electrical devices should be graphically ensured by a smooth sine wave, but in practice it is more reminiscent of an cardiogram. A surge protector can filter out unnecessary harmonics and interference.

How the filter works

A surge protector device, which has a basic configuration, will not pose any difficulties in eliminating interference; it does this daily and repeatedly. The provocateur of such an impulse (a jump in the network) can be a static discharge of atmospheric electricity. For this reason, the filter is equipped, in addition to fuses against network surges, with a gas-discharge fuse, which responds to a wide amplitude and rapid impulse of atmospheric electricity.

The filter device uses the resistance property of the induction coil, which can be expressed as follows: the higher the frequency of the current, the higher the resistance of the coil - this allows you to smooth out high-frequency interference (sinusoids with short periods). For this reason, the filter has two coils, which are included in the neutral and phase wires. Low-frequency interference can be suppressed by a resistance having a nominal value of more than 1 ohm, which is also connected in series.

To eliminate short-term pulses, a varistor is built into the filter - this is a semiconductor element that, at low voltage in the network, acts as a resistance (resistor) and does not allow current to pass through. When the voltage rises, pulse currents pass through the varistor. In other words, in the filter it is connected in parallel with the load to absorb high voltage pulses, it smoothes out their influence.

A high-quality filter socket for electrical equipment should consist of the following elements:

• induction coils - two pieces, with a rating from 60 µH to 200 µH, which are connected in series;
• varistor with a voltage of 470 volts, which is connected in parallel with the load;
• capacitors;
• resistance from 1 Ohm to dampen low-frequency interference.

You can often find products on sale that pass off as a surge protector, but they cannot be such, since they do not contain the elements necessary for its operation.

How to make the right choice

The choice of a surge protector, according to experts, should begin with an external inspection. It must have a mandatory button that allows you to force a network shutdown. A surge protector is a device in which the number of electrical equipment power sockets matters; this depends on the product manufacturer; usually one filter powers several devices of different power.

The correct choice is based on the documents accompanying the product; they reflect all the information necessary for the buyer. The passport must indicate all the functions that the filter has from the manufacturer. Pay attention to the value of the pulse load, it indicates the filter’s ability to withstand significant voltage drops in the network. Some models of surge protectors can withstand the effects of atmospheric discharges on the power source.

For household consumers of electrical energy, the standard length of the device’s power cord is 1.8 m, but there are other options for the cable feeding the filter - 5 m. The presence of different numbers of fuses in the device (but not less than three) should guarantee protection against various types of interference. If the device does not have an LED button, then it is a simple extension cord.

How to choose a surge protector for your computer

Now every family in the cities has a computer; filters have been developed for them that perform the protective function of computer equipment from voltage surges and high frequencies in the network. Users can often visually confuse the filter with another device - a UPS, but the filter functionally protects the PC from overvoltage; it does not support power supply in the event of a network outage, like a UPS.

A surge filter is needed to provide filtering of the network voltage for a computer; it solves the following problems:

• control of impulses passing through it, which can cause the PC to automatically restart without saving data on the monitor;
• ensuring smoothing of high-frequency pulses that occur when powerful consumers are simultaneously turned on.

Experts recommend the APC product to protect their own computer equipment; this device is perfect for home use, as well as in small offices.

The model has five sockets and is considered inexpensive. The device is average in terms of its main characteristics. It is recommended to connect telephone equipment, fax, and PC through this filter. Cable length - 1.8 m.

Manufacturers also offer better protection - this is the Pilot X-Pro model, which is more resistant to load at high frequency surges. According to the data sheet, the filter of this model absorbs up to 650 J, converting it into heat energy.

Selecting a filter for an LCD TV

The protection of the home theater, as well as other video equipment, is provided by a surge protector for the TV, which must be guaranteed to protect the equipment from interference and voltage surges. Special filters for TVs have an automatic shutdown when a short circuit occurs in the network. Experts recommend the APC PMF83VT-RS filter model for these purposes, which is shown in the photo:

This model costs about 3 thousand rubles, has a coaxial input, an indicator, a maximum load current of up to 10 amperes, a power of 2.3 kW, a voltage of 230 volts, has 8 grounded sockets, cable length - 200 cm, the sockets are located on both sides, has protection for TV signal. Each socket can be forcibly turned on or off; there is a general socket switch. Which surge protector to choose is a question that the average person always faces because of the cost of the devices.

There is a cheaper filter option for a TV that costs 1 thousand rubles, this is MOST Elite ERG, pictured:

The performance parameters of this filter are the same as in the APC PMF83VT-RS model, but it has only five sockets.

Types of filters

Experts distinguish network filters into three categories, which are determined by their level of protection, namely:

• basic version, essential protection - marked Essential, recommended for home equipment: microwave, household equipment (vacuum cleaner, iron, other appliances);
• universal filter - marking in the Home/Office passport, recommended for computer equipment, modern LCD TVs;
• Performance category filter, recommended for working with voltage-sensitive equipment, has a fairly high cost.

To correctly select a filter for the electrical equipment of an apartment or office, there is a procedure for considering the characteristics of the proposed device:

• load power according to the technical data sheet;
• number of simultaneously connected equipment;
• type of sockets;
• length of cable;
• number of fuses;
• mandatory presence of an LED indicator;
• presence of USB output.

According to experts, for home use it is quite enough to have a filter that can withstand up to 10 amperes of load at the same time. To connect a PC, a device with at least five sockets is recommended; the length of the power cable from the socket to the filter can be selected individually, but a standard length of 180 cm is quite sufficient. Among the best devices of this type offered on the market are the following: Defender, BURO, APC and Pilot, as well as Vektor and DNS, which develop and sell models of all 3 protection categories.

Conclusion

Experts do not recommend using devices of this type in a chain, in other words, powering one filter from another, which leads to an increase in the current value. It is not recommended to connect equipment with a high input voltage through a network filtering device, such as heating devices (electric heater), air conditioner, vacuum cleaner. It is not recommended to connect a UPS for a computer through a filter; there is a high probability of damage to the “PC uninterruptible power supply” protection circuits.