What to install in the apartment: a stabilizer or a voltage control relay?

For Russian electrical networks, voltage fluctuations are a common thing, so many people are wondering: is it worth buying a 220V voltage stabilizer for an apartment? Or is it better to buy a protective relay? Most electricians say unanimously: a voltage control device in an apartment is necessary. But what type of protection to choose can be decided only after carefully studying the conditions.

Why does the voltage fluctuate?

The first step is to understand why voltage fluctuations may occur and assess the risk of this occurring in your home.

The requirements of the standard (GOST 29322-92) specify the parameters of electrical power in one phase (230 V) and between two phases (400 V). However, in many villages and urban settlements there are quite frequent fluctuations in the voltage value. And for cities, the situation when the readings of a voltmeter in a socket deviate from standard values is not something impossible.

Voltage fluctuations can occur for several reasons:

In case of phase imbalance (uneven distribution of load between phases), the voltage drops on the most loaded branch, and its increase occurs on less loaded branches. It is the frontal misalignment that is the main cause of short-term fluctuations.
Zero burnout. Since the neutral wire is relatively thin, its breakage or burnout is more likely than phase burnout. In this case, 380 V appears in the sockets.
Short circuit of neutral and phase wires also creates 380 V in sockets.

Problems with the quality of electricity supply are typical for older housing stock. However, judging by reviews from thematic forums, even apartments in new buildings are not completely free from this scourge.

Since all devices are designed for a standard voltage value, any fluctuation can lead to serious consequences. Thus, when the voltage decreases, air conditioners and refrigerators often fail (due to low voltage, the compressor motor cannot start and the windings burn out). High voltage is harmful to almost all household appliances and electronics.

Voltage stabilizer and relay: main differences

Since a power surge can destroy many household appliances, finding protection against this problem remains an important task in electrical engineering.

Today there are two main solutions:

The relay controls the voltage value in the network. If its value deviates from the norm so much that it goes beyond the specified limits, the control device will turn off the power supply and protect the connected electrical appliances from burnout.
The stabilizer also cuts off the electricity supply if the voltage becomes too high or low. However, this device is capable of changing the voltage value within certain limits, making it closer to the reference value. So, if the voltage is set to 220 V with a minimum of 215 V, the stabilizer will turn off the network when the voltage drops to 213 V, and raise the voltage to 218 V to the reference value.

The choice between these devices is very difficult. Each class has its own advantages and disadvantages. Therefore, in some situations it is better to install a control relay in the panel, and in others - a stabilizer.

Advantages and disadvantages of stabilizers

The advantages of a stabilizer include the ability to equalize voltage. The most advanced devices of this type (inverter class) maintain the specified parameter with a deviation of no more than 1%. But even the cheapest stabilizer models will not allow deviations of more than 5%. Of course, this mode is most favorable for electrical appliances and can extend their service life.

Stabilizers have high efficiency. Another plus is the minimal impact on the quality of the analog signal. It is easy to connect stabilizers to the network, so there is no need to invite a specialist to install this protective device.

But there are also disadvantages. Stabilizers are quite large in size, and the most powerful models make noticeable noise and heat up during operation. The cost of these devices is also quite significant.

The individual use of stabilizers allows you to compensate for shortcomings. Devices for connecting loads up to 1.5 kW remain relatively compact and affordable, which cannot be said about models designed for loads of 3 kW or more.

Which voltage stabilizer to choose: review of popular models

Today there are dozens of stabilizer models. They differ in design (mounted and floor-mounted), network type (single- and three-phase), design and many other parameters. The price of different models can also differ by an order of magnitude or more. The optimal choice of stabilizer for each case is a topic for a separate detailed article.

However, some models enjoy stable popularity due to the optimal combination of weight, size, electrical and price characteristics. Let's talk about four in more detail:

"Voltron Energy" The device is capable of stabilizing voltage in the range from 105 V to 265 V.It can operate over a wide temperature range, making this model an excellent choice for a farmhouse. The device is safe to use, protected from power surges and short circuits. The only drawback is its large dimensions and weight.
"Resanta ACH-500/1-C". An excellent choice for the home: an inexpensive, low-noise and easy-to-control floor-mounted stabilizer. Large and clear display numbers, convenient controls (only two buttons), simple connection of consumers make this model ideal for use by people with minimal knowledge of electrical engineering.
"Rucelf boiler-600". This is a single-phase wall stabilizer that can withstand indoor air humidity up to 80%. Thanks to these characteristics, the model is excellent for powering water heating boilers. Input voltage is from 150 V to 250 V. This makes the model quite universal. The main disadvantage is the relatively low maximum load.
Sven VR-L600. A relay model that provides stabilization in the range from 184 V to 285 V. Its main advantages are the ability to operate in two-phase circuits, compact dimensions, and reasonable price. Among the disadvantages are the not very convenient shape of the case (the possibility of mounting it on the wall is not provided) and the low accuracy of voltage equalization.

Of course, the listed models can only serve as approximate guidelines when choosing. But a large number of positive reviews from professional electricians and ordinary users allow us to call them leaders in consumer preference.

Selecting a voltage relay

Phase voltage control relays have their advantages over stabilizers.Most of their models are compact and easily mounted on a DIN rail in a panel. The cost is also not shocking. Another advantage is a faster response to a voltage surge than a stabilizer.

Among the many models presented on the domestic market, users highlight:

Products of the Electronics plant (Donetsk), manufactured under the Zubr brand. The advantages of such relays are affordable cost, the presence of a voltage indicator, and compactness. Due to the intricacies of patenting, the products of this enterprise in Russia are found under the RBUZ brand, since the ZUBR brand is already occupied by another company.
UZM-51M, produced by Meander CJSC. This is a simple and reliable relay to connect, which occupies only 2 modules on a DIN rail. The device is capable of operating in the range from 100 V to 290 V. Disadvantages include the impossibility of installation in switchboards located on the street, as well as the lack of voltage indication. However, due to the low price and compact size, the latter problem can be solved by installing it together with a VAR relay.
Series of relays RN-111, RN-111M, RN-113 from the Novatek company. Products made in Russia. Single-phase devices of the 111 series are designed for installation in the range from 160 V to 280 V with a power of up to 3.5 kW. Up to 7 kW can be supplied through the RN-113, but the contact group may not be able to cope with wires of sufficient thickness.

There are other models of voltage relays, both domestic and foreign.

Before purchasing this or that relay, you should look through thematic forums. This will allow you to timely track the appearance of defective lots on the shelves and refuse to purchase.

Let's sum it up

It is necessary to install protection against voltage fluctuations in modern conditions.The choice between relays and stabilizers is made based on the tasks that the protection system must solve and the available budget. The optimal combination of price and protection efficiency is most often achieved by installing a general voltage relay for the entire apartment and stabilizers for individual, most valuable household appliances.