Comparison Kemot SER-2000 2 kVA / 1500 W vs Aruna SDR 3000 3 kVA / 1800 W

The maximum active power load permissible for this model.

Active power is the power consumed by AC devices for useful work or heat generation. Additionally, such devices consume reactive power — used for the function of specific components, primarily capacitors and inductive coils. The apparent power, measured in volt-amperes (kilovolt-amperes), is the sum of active and reactive power; see below for more on that. Here, we note that in simple household situations, active power data in watts is usually sufficient for calculations. This parameter is considered key when choosing voltage stabilizers for washing machines and for dishwashers: for the former, an optimal power range is from 2 to 5 kW, and for the latter, from 1.8 to 2.5 kW.

Regardless, the total active power of the connected load should not exceed the figures specified in the stabilizer's specifications. For full assurance, it's wise to have some reserve, though it shouldn't be too large — increasing permissible power significantly affects the size, weight, and price of the device. It's also worth mentioning that there are formulas to convert active power consumption to apparent power, considering the type of connected electrical appliance; these formulas can be found in specialized sources.


It should be noted that manufacturers don't always specify power in watts, sometimes only providing values in kVA. In such case...s, we apply an approximate conversion. Overall, while the value is approximate, it adequately describes the stabilizer's capabilities and helps match specific needs.

Maximum total load power allowed for this model

In electrical engineering, total power is referred to as the power that accounts for both active and reactive power; the former is discussed above, and the latter can be described as the influence of windings, inductors, and capacitors on the operation of AC networks. Total power is the main parameter for calculating equipment loads in professional electrical engineering and is denoted in volt-amperes (VA), and for stabilizers, in kilovolt-amperes (kVA). Note that for convenience, different types of powers in electrical engineering are designated with units of different names. That's why the power indicated for a stabilizer in watts usually does not equal its power in VA.

When choosing a stabilizer for some household appliances, data on active power is often sufficient, but if possible, it is better to use total power. In particular, this parameter is key when searching for a stabilizer for a refrigerator or a stabilizer for a boiler: in the first case, the optimal value is considered to be 0.4 – 1 kVA, and in the second — from 0.1 to 0.7 kVA. However, in any case, you should choose a specific model so that its total power is not lower than the total power of the entire connected load — and it's better to have a reserve (in case of unforeseen circumstances or connecting additional equipment). At the same time, it should be noted that powerf...ul models are characterized by large dimensions and weight, and above all — high cost; therefore, it is not always wise to chase maximum figures.

It should be noted that manufacturers do not always specify power in kVA, and there is only a value in watts. In such cases, we apply an approximate recalculation. While approximate, the value sufficiently describes the capabilities of the stabilizer and helps select according to specific needs.

We also note that there are formulas that allow deriving the optimal total power of the stabilizer based on data on active power and load type; these can be found in specialized sources.

The voltage range at the input of the stabilizer, at which it is able to operate in normal mode and supply a constant voltage of 230 or 400 V to the load (depending on the number of phases, see above). The wider this range — the more versatile the device, the more serious power surges it can extinguish without going beyond the standard operating parameters. However, note that this parameter is not the only, and not even far from the main indicator of the quality of work: a lot also depends on the accuracy of the output voltage and the response speed (see both points below).

Also note that some models may have several modes of operation (for example, with 230 V, 230 V or 240 V output). In this case, the characteristics indicate the "general" input voltage range, from the smallest minimum to the largest maximum; the actual ranges for each particular mode will vary.

In addition, there are stabilizers that can operate outside the nominal input voltage range: with a slight deviation beyond its limits, the device provides relatively safe output indicators (also with some deviations from the nominal 230 or 400 V), but if the drop or rise becomes critical, it works appropriate protection (see below).

The largest deviation from the nominal output voltage (230 V or 400 V, depending on the number of phases), which the regulator allows when operating in the normal input voltage range (see above). The smaller this deviation, the more efficiently the device works, the more accurately it adapts to “changes in the situation” and the less voltage fluctuations the connected load is exposed to.

When choosing for this parameter, it is worth considering first of all how demanding the connected devices are for voltage stability. On the one hand, high stability is good for any device, on the other hand, it usually means a high price. Accordingly, it usually does not make sense to buy an advanced stabilizer for an unpretentious load like light bulbs and heaters, but for sensitive devices like audio systems or computers, it can be very useful.

The number of sockets for 230 V with grounding provided in the design of the stabilizer.

Some electrical appliances, such as refrigerators and washing/dishwashers, must be grounded when connected. This point should not be ignored — there is a risk of a serious electric shock. Accordingly, the number of sockets with grounding corresponds to the maximum number of such devices that can be simultaneously connected to the stabilizer without the use of splitters. At the same time, ungrounded devices can also be connected to such sockets.

The presence in the design of the stabilizer of at least two pairs of terminals — at the input and at the output. Unlike sockets, which are designed for frequent connections and disconnections, the terminal connection is designed to permanently secure the wires — roughly speaking, "attached — clamped — forgot." It does not involve direct connection of electrical appliances, usually the power from the terminals goes further into the mains and is already distributed through it to individual sockets in the room. Accordingly, this option is typical for powerful models (on average from 3 kVA and above, see "Power"), which are designed for installation in one place as a permanent element of the power grid. Often such stabilizers do not have their own outlets at all — only terminals.

The degree of protection of the internal components of the stabilizer from various undesirable influences from the outside — first of all, from the ingress of moisture and foreign objects. The IP (ingress protection) standard is used to describe the protection provided by an enclosure.

In marking according to this standard, two digits are usually used — for example, IP54. The first digit describes the degree of protection against various solid objects (up to and including sand and dust). Its specific meanings may be as follows:

1 — protection against objects measuring 50 mm or more (for comparison: the average male fist will no longer pass even through the largest hole in such a case).
2 — from objects with a size of 12.5 mm or more (comparable to the thickness of a finger on a hand).
3 — from objects with a size of 2.5 mm or more (we can talk about protection against accidental contact with most standard tools).
4 — from objects with a size of 1 mm or more (for example, most wires).
5 — medium degree of protection against dust (it is allowed to get inside a certain amount of dust that does not affect the operation of the device).
6 — the maximum degree of protection against dust (its ingress is practically excluded).

The second digit, respectively, describes the resistance to moisture:

1 — minimum degree of protection — the device, placed in the working position, is resistant to individual drops falling vertica...lly on it.
2 — vertical drops are allowed when the device deviates from the working position by less than 15 °.
3 — splashes flying at an angle of up to 60 ° from the vertical are allowed; rain protection.
4 — resistance to splashes from any direction; wind and rain protection.
5 — resistance to water jets; protection from heavy rains, storms.
6 — short-term ingress of large volumes of water is allowed — for example, when a wave hits.
7 — the possibility of short-term immersion under water to a shallow depth (up to 1 m).
8 — the ability to work at a depth of 1 m and for a longer time.

One of the numbers can be replaced by the letter X — this usually means that the device does not have official certification in the corresponding direction of protection. In some cases, this suggests that there is no such protection at all — for example, the IP2X case is most likely not designed for any water ingress at all. However, it can be the other way around — for example, IPX7: a housing with the ability to submerge under water will certainly be well protected from dust, even if this is not officially announced.

Of course, it is worth choosing an option for this parameter, first of all, taking into account the expected operating conditions: for example, for a dry utility room, water protection is useless (it will only cost extra money), but in a damp basement, such a case can be very out of place. However, note that no protection provides absolute guarantees and does not eliminate the need to comply with safety rules.

The presence in the design of the stabilizer of a special handle for carrying the device from place to place. This feature is useful primarily for powerful and, accordingly, heavy devices, which would be inconvenient to hold directly by the case. And in the most "weighty" models, which are not designed to be carried alone, there are several handles.