In the process of searching for methods of protection against voltage surges and sags, we recommend using the catalog, which allows you to choose a stabilizer for an apartment or house, sorting equipment by parameters such as power, design, purpose or installation method, and comparing prices in different online stores.

Causes of power surges in the network

The outlet is far from always exactly 230 V. The voltage in the household electrical network may be slightly higher or significantly lower than the standard value. Sometimes the voltage jumps up and down continuously, and in some circumstances there are destructive high-voltage spikes. This "behavior" of the current can have many explanations.

  • natural causes. Each time household appliances are turned on or off, small fluctuations in the amount of current consumed in the network occur. Such fluctuations must be automatically stabilized by the equipment on the power supply line. But stabilizing schemes do not always have time to work the way they are required to.
  • Technogenic factors. The deterioration and moral obsolescence of some sections of electrical networks leads to the fact that the system cannot even cope with the calculated load. Moreover, the number of household appliances and, accordingly, the load on the network are growing from year to year.
  • natural phenomena. A lightning strike on a power line or a broken wire during a hurricane are emergencies that cause high-voltage “bursts” or phase imbalances.
  • Violation of the rules. Connecting new groups of consumers (individual houses or entire residential complexes) to transformer substations that are not designed to serve such a number of subscribers leads to equipment operating at the limit of its capabilities or even beyond them. In such cases, it is simply physically impossible to provide stable 230 V.

This list shows that practically no one is immune from problems associated with voltage drops in the electrical network.

The Qoltec 50722 stabilizer reports any slightest change in input and output current parameters using a bright color LED display.

How dangerous are voltage fluctuations for household appliances

Deviations of ± 5% from the nominal 230 V are considered normal, and ± 10% are acceptable. It is the last parameter that manufacturers are guided by, laying in the design of household appliances the ability to work normally at a voltage that is slightly out of line.

But more significant voltage surges and drops, regardless of their causes and nature, adversely affect the performance of household and computer equipment (even simple light bulbs can burn out if the voltage jumps up by 25%).

Both too high and too low voltage in the network are equally harmful. When jumping up, electronic boards burn out or fuses blow, control units “knock out” errors and refuse to work. With drawdowns down, the equipment does not have enough voltage for normal operation: the electric kettle heats the water more slowly, and the electric motors of pumps or compressors of refrigerators and air conditioners simply do not start. And for devices such as automation that controls the operation of modern gas and solid fuel boilers, a stable voltage is critical.

The APC Line-R LS1000-RS stabilizer has such a laconic design that it does not have a voltmeter at all.

Types of stabilizers

To protect household appliances that are vulnerable to power surges, it makes sense to invest in upgrading your home power system and buy a suitable stabilizer.

A voltage stabilizer is, roughly speaking, a personal transformer substation operating in automatic mode. Depending on the size, power and design, it can serve the whole dwelling or only a separate section of the network to which the most important equipment is connected. Receiving a current with over or under voltage at the input, the stabilizer brings it to a normal value and gives the consumer a standard 230 V (with a small error).

The stabilizer has a primary winding (it receives current from the main) and a secondary (current is removed from it for consumers). The principle of operation of the device is based on the fact that when the number of turns on the primary winding changes, the current on the secondary changes. By controlling the position of the current collector device, which moves along the windings or “jumps” from one contact to another, it is possible to ensure stable output current parameters, regardless of voltage surges and drops in the line.

Depending on the technology for implementing feedback and controlling the current collector device, stabilizers are:

  • relay - a key element of the design is a relay that provides switching between groups of contacts;
  • electromechanical - the servo drive moves the movable contact directly along the transformer windings;
  • electronic( triac and thyristor) - semiconductor devices that perform the functions of a relay are responsible for switching between groups of contacts;
  • combined - represent an attempt to combine electromechanical and relay stabilizers in one device;
  • inverter - carry out double current conversion (from AC to DC and vice versa) using an inverter, providing a stable output voltage.

The device is a simple and inexpensive relay stabilizer.

Stabilizers of different types differ greatly in price (relay ones are cheaper, electronic ones are more expensive), response speed, voltage regulation accuracy, size, and even noise. Below we will look at how to choose a voltage stabilizer for a house or apartment in order to take into account all the parameters, characteristics and features of different types of equipment.

Relay Stabilizers

What power should be the voltage stabilizer

To decide which stabilizer is better to choose for an apartment or a private house, you need to know what and how we plan to protect against power surges and voltage drops. In apartment buildings, refrigerators and electronics suffer from power surges, first of all. Owners of country houses have an additional headache in the form of powerful borehole or surface pumps, which are critical for autonomous water supply, and boilers that provide home heating. Therefore, it is necessary to calculate the total power of all electrical appliances that will be connected to the line protected by the stabilizer. Everything is taken into account: from large household appliances to light bulbs.

Please note: when choosing a stabilizer, it is not the active power of consumers that is summed up (measured in kilowatts, indicated in the passport characteristics), but the total power (measured in kilovolt-amperes, takes into account inrush currents). For some types of household appliances, the total power (kVA) exceeds the active power (kW) by two to three times.

In most cases, a stabilizer with a capacity of up to 10 kVA is enough for a small one-story private house, and 3-5 kVA is usually enough for an apartment of two or three rooms. A device with a power of 1000 VA can handle the protection of the refrigerator, a more powerful model is required for the washing machine, and for the boiler you can choose a relatively low-power voltage regulator (within 700 VA).

Inverter Voltage Stabilizers

Advantages and disadvantages of different types of stabilizers

In addition to the total power of consumers, it is necessary to take into account the features of different types of devices. After all, each type of stabilizers has its own advantages and disadvantages due to their design, and, accordingly, different areas of application.

For example, in rural areas and the private sector, it often happens that consumers receive current with stably low characteristics (and in the immediate vicinity of a transformer substation - stably overestimated), but at the same time there are no special jumps. In such situations, a relay or electromechanical stabilizer with a wide operating range and a large power reserve would be a good solution. On the other hand, these devices are not well suited for situations where the voltage is constantly jumping (for example, if a restless neighbor with a welding machine is connected to your line). Continuously reacting to jumps and switching from contact to contact every second, the relay stabilizer will bring you to a nervous tick with its loud clicks, and the electromechanical in such a situation will quickly fail the servo drive. Therefore, for an apartment or house connected to a network with jumping voltage, it is better to choose an electronic stabilizer. It works silently, reacts faster and regulates the output voltage more accurately (although its price is higher).

A three-phase stabilizer for a private house is, in fact, three single-phase stabilizers installed in one housing.

Single-phase or three-phase stabilizer

Owners of private houses also often have questions about which stabilizer to choose: single-phase or 3-phase. Even if three-phase electricity with a voltage of 400 V is supplied to your house, you can ensure voltage stabilization in the network using conventional single-phase devices, installing them one for each phase. Many household three-phase stabilizers are sold as sets of three identical single-phase appliances. Sometimes in a three-phase network, you can even get by with a single single-phase stabilizer, protecting with it only the phase to which the equipment that is critical for the functioning of the house (pump, boiler, refrigerator, etc.) is “hooked up” for the functioning of the house.

Wiring diagram of three single-phase stabilizers to protect a three-phase network.

Other ways to protect equipment from voltage surges

No article on the selection of stabilizers would be complete without highlighting alternative options for protecting household appliances from voltage surges. After all, there are other ways to protect consumers from sudden surges and drawdowns in the network. But it should be noted right away that none of the devices listed below completely replaces the stabilizer, since it performs slightly different functions.

  • The voltage control relay cannot maintain a stable 220 V, but it can turn off a section of the electrical circuit if the current characteristics go beyond a certain “corridor”. It can be designed as a device that is mounted on a DIN rail in an electrical panel(to protect the entire line), or plugged directly into a socket(to protect a single consumer). The relay has adjustable thresholds and a delay setting so that the device does not react to short-term and minor jumps and drawdowns.
Voltage Relay

  • Surge protectors in the form of extension cords or devices that are plugged into a socket protect electronics well from interference and surges that occur when powerful consumers (like refrigerators and welding machines) are turned on and off. They also have fuses that operate when a certain current threshold is exceeded, and varistors that protect against high voltage impulses (they occur, for example, during short circuits or lightning strikes in power lines). Therefore, all consumer electronics, such as computers, televisions, audio systems, etc., should be connected through surge protectors. Network filters are inexpensive and perform their functions very effectively, despite their rather limited capabilities.
Gas Filters

  • Uninterruptible power supplies are able to switch to battery operation if the mains voltage drops below a certain limit. They are also usually equipped with devices for protection against short circuits and transients. Many UPSs allow you to regulate the output voltage to ensure stable power even if there is no 230 V in the network.
UPS

From a brief description of alternative protection methods, it can be seen that sometimes it is worth buying another device instead of a stabilizer. For example, installing a relay looks more rational if voltage drops in your network are rare. And an uninterruptible power supply is better suited for protecting a workplace with a computer, because it not only “corrects” minor current defects in the network, but also gives some time to save important documents if the electricity goes out.

Video about voltage stabilizers

If you do not have time to read such a long article, we advise you to watch our video on how to choose a voltage stabilizer, and in 5 minutes understand the main criteria for selecting equipment for your apartment or private house.