Choosing a Voltage Stabilizer

Unstable voltage is bad anyway. Both lowering and increasing the voltage in the network can negatively affect household appliances, not to mention our nerves. With power surges up and down, household appliances will at best work abnormally or turn off. At worst, it will “burn out”, break down from the same frequent involuntary on / off. At one time, Samsung conducted a study that showed that 80% of problems with household appliances are connected precisely with power surges. How not to be left without a working refrigerator, air conditioner, TV, computer or some kind of domesticated machine during power surges? How to protect equipment from voltage drops? Of course — you need to buy a voltage stabilizer! But the stabilizer stabilizer is different. What should be considered when choosing this device?

Stabilizer, goodbye!

Home appliances of well-known brands often already have a built-in stabilizer and does not need additional

Please note that the purchase of a stabilizer is not justified for all household appliances. When is a stabilizer not needed? For example, if you use household appliances of a well-known brand, then it is possible that it already has a built-in stabilizer and does not need an additional one. Samsung has a similar technology called Volt Control (usually it is voltage stabilization within 165-290V with simultaneous protection against power surges up to 400V), LG has AVP technologies (Auto Voltage Protection, usually effective in the range of 170-290V), there are similar technologies and from other manufacturers.

Decent switching PC power supplies with an active power factor correction system (APFC) are also perfectly capable of doing without a stabilizer, as they stabilize the voltage on their own. In general, with the spread of switching power supplies, the need to use voltage stabilizers has decreased significantly. In general, before connecting the stabilizer to any home appliances, make sure that it is really needed there. Otherwise, all the benefits of the stabilizer will be reduced to air heating.

What unites the stabilizer and the machine?

You should not buy a stabilizer with a current "for reserve", if the circuit breaker is designed for low current

When the input voltage drops to provide the desired output power, the regulator is forced to consume more current. However, you should not purchase a "super powerful" stabilizer with a high rated current "for reserve", for example, 25 amperes, when your quite typical home circuit breaker is rated up to 16A. And the “plug” fuse in some old house may still be suitable for current only up to 6A. If too much current flows through the circuit breaker / fuse, the protection will work, and the house will be completely de-energized. The effect of the powerful stabilizer will be more than deplorable. Of course, you can install more powerful circuit breakers / fuses in the house, but this is already fraught with dangers that we will not consider in this article. Better just remember the necessary correspondence between the maximum current of the machine (fuse) and the stabilizer. Quite powerful stabilizers suitable for ordinary houses with an acceptable load current are, for example, models Sven AVR-3000 LCD 3 kVA / 2400 W , Powercom TCA-3000 3 kVA / 1500 W Price from 2 046 up to 3 137 ₴, Luxeon SVR-3000 3 kVA / 2100 W Price from 3 359 up to 4 199 ₴ etc.

Phase shift

When choosing a stabilizer, you should consider whether you need a device for a single-phase 220V network, or you need a stabilizer for a three-phase 380V network. From 380V can be powered, for example, various machines.

If, in the presence of a three-phase network, there are no three-phase electrical appliances themselves, and only a single-phase load is used, it is rational to use three single-phase stabilizers instead of one three-phase one. This can not only be cheaper, but also give a significant advantage: in the event of a complete lack of power in one of the phases, devices connected in other phases will not be affected. Whereas a three-phase stabilizer will completely de-energize connected consumers with a similar problem.

Good two-phase stabilizers are Forte ACDR-10kVA 10 kVA Price from 11 700 up to 15 980 ₴, Luxeon FDR-5000VA 5 kVA / 3500 W Price from 4 600 up to 6 263 ₴, Eleks Hibrid 9-1/40 9 kVA , three-phase — Ukrtehnologija Optimum+ 5000x3 15 kVA Price from 49 800 ₴, Eleks Amper 12-3/25 16.5 kVA Price from 53 500 ₴.

Entry order

To choose a stabilizer, it is desirable to take measurements voltage changes in the network for at least a day current

In order to select the necessary stabilizer, it is highly desirable to measure the change in voltage in the network over a certain period of time, at least a day, and even better — over several days. This will make it possible to more accurately determine the magnitude of the voltage fluctuation and select the optimal stabilizer model. When choosing, it is desirable, of course, to focus on devices with a slightly wider range of permissible input voltage than was measured.

If the magnitude of the voltage fluctuation in the network is unknown, you will have to buy a stabilizer at random. And the greater the margin for the amplitude of the input voltage, the better, although such models are more expensive. Good stabilizers with a large input voltage range are Dnipro-M ASN-5000P 5000 W , Sven AVR-2000 LCD 2 kVA / 1600 W , Phantom VNTU-842 6000 W .

Cause time

If the stabilizer responds to a change in voltage in the network very slowly, for example, within a second or two, then a sensitive electrical appliance may “have time” either to turn off or “burn out” due to unacceptable voltage. Therefore, if you have cool and very sensitive electronics, as well as lighting fixtures, choose models with the shortest possible voltage stabilization time, on the order of fractions of a second. We will talk more about this parameter when we describe the types of stabilizers.

Accuracy decides

For precision (measuring and controlling elements of smart home devices, Hi-Fi systems, etc.) and lighting devices, devices with a voltage stabilization accuracy of up to 3% are recommended. For undemanding household equipment, devices with an accuracy of up to 7% are suitable. Everything above is for very undemanding heaters. The accuracy and quality of stabilization directly depends on the type of stabilizer, remember this. A stabilizer model that is perfect for an air conditioner may not be suitable for a lighting system at all(causing brightness flicker) or sensitive audiophile equipment that does not allow significant deviations from the nominal power parameters.

For example, stabilizers with high stabilization accuracy up to 3% are Eleks Amper 12-1/40 9 kVA , Luxeon WDS-10000VA SERVO 10 kVA / 7000 W Price from 10 626 up to 14 268 ₴, RUCELF SDW-10000-D 10000 W , Strum STR-3000 3000 W Price from 8 790 up to 9 405 ₴, Ukrtehnologija Standard 9000 9 kVA Price from 17 100 up to 20 900 ₴ etc.

Bins of power

Peak power consumption of some appliances (vacuum cleaners, air conditioners) at the time of switching on, may be several times higher than the nominal

The key characteristic of the stabilizer is the power of the connected load. You can approximately determine what kind of power the stabilizer is needed by simply adding the power of all electrical appliances connected to it. When calculating, the total power consumed by the equipment, which consists of an active and reactive component, should be taken into account. The total power of any electrical appliance is usually indicated in volt-amperes (VA), and the active power in watts (W). The total power is related to the active so-called power factor.

Resistive load assumes that all consumed electricity will be converted into heat. Devices with predominantly active power include heating devices (boilers, heaters, electric stoves), electric kettles, irons, incandescent lamps, etc. For an active load, the power factor is 1. Thus, for a 2 kW boiler, a 2 kW stabilizer is sufficient.

Reactive loads are all that consumed electricity that is not converted into heat. First of all, these are inductive and capacitive loads. Reactive power is quite large in the vast majority of consumer electronics, especially those containing electric motors. For household appliances, the power factor is usually 0.6 — 0.8. Accordingly, on a refrigerator with a specified power of 400 W at a power factor of 0.8, the total power required at the output of the stabilizer will already be 500 VA. If no data on the power factor of the device, then professionals recommend taking an average value of 0.7 for calculation, if this is not a device with a purely active component of consumption. Plus, manufacturers recommend installing stabilizers with a margin for the required power of 20-30% of the calculated one. Indeed, when the voltage in the network decreases, the power at the output of the stabilizer may also fall to one degree or another.

But it's not all about power. Some household electrical appliances have high starting currents. These are compressors, refrigerators, pumps, vacuum cleaners, air conditioners, devices with asynchronous electric motors and other equipment. At the time of switching on, the peak power consumption of such devices can exceed the rated power in normal operation by several times (!) If you plan to connect such equipment to the stabilizer, it is recommended to choose a stabilizer with a rated power of at least 3 times the rated load power in order to avoid overloading the stabilizer and risking damage to the device. Powerful stabilizers for such cases — Ukrtehnologija Infinity 20000 20 kVA Price from 37 114 up to 41 030 ₴, RUCELF SDV-30000 30 kVA / 24000 W , Eleks Herz M 16-3/50 33 kVA Price from 93 000 ₴ etc.

different types

Let's move on to the main types of stabilizers.

Electromechanical stabilizers(they are also servo-driven and electrodynamic) correct the voltage using an autotransformer, the regulation of which is carried out using a rotary brush contact driven by an autonomously controlled servo drive. Due to their design, electromechanical stabilizers are not very suitable for use in networks with frequent, strong and sharp voltage drops — due to the large switching delay and mechanical wear of the structural elements.

Typical electromechanical stabilizers are RUCELF SDV-3-20000, Luxeon A1S-20KVA SERVO, IEK SNI 1-20 kVA.

Relay stabilizers are also autotransformer stabilizers, however, voltage regulation here is carried out in steps by switching the windings of the power autotransformer using electromechanical relays.

Relay stabilizers — LVT ACH-600, Forte TVR-500VA, Proton SN-2000, Luxeon EW-12000, etc.

Triac (thyristor) stabilizers are similar in principle to relay stabilizers, however, instead of a relay, electronic triac (thyristor) switches are used here to switch the transformer windings. The advantage of this solution is the absence of noise when switching the windings of the autotransformer, the lower weight of the device and the absence of mechanical wear of structural elements.

The type of seven-storey stabilizers includes Eleks AMPER 12-1 / 50, Ukrtehnologija NORMA 7500, Volter Etalon 7. Thyristor models — Phantom VNTU-842, Eleks HERZ M 36-1 / 40, etc.

Ferroresonant voltage regulators are structurally composed of a saturated core choke, an unsaturated core choke and a capacitor connected to it, which serves to increase the power factor according to the current resonance circuit.

This type of stabilizer is considered obsolete, although in the past these stabilizers were very common — it was with them that old Soviet TVs worked.

Double conversion stabilizers differ in that they first convert the alternating current to direct current, and then re-convert it to alternating current, which makes it possible to achieve an almost perfect sinusoidal voltage waveform at the output.

Ariana A 1200, Leoton NN-300/450 are double conversion stabilizers.

Combined(they are also hybrid) stabilizers, as you might guess, integrate several types of stabilization devices at once. Usually, this is a combination of an electromechanical and relay stabilizer. The peculiarity of the device is that with small voltage drops, the electromechanical method works, and with sharp strong power surges, a relay module is connected to the case, which allows you to quickly, although not very accurately, stabilize the voltage. Usually, the overall accuracy of hybrid stabilizers is not very high and can go up to 10%.

Combined stabilizers include Eleks HERZ RELE 9-1/40, Eleks HERZ RELE 9-1/25 and Eleks HERZ RELE 9-1/32.