Rated power
The nominal power of a generator is the highest power that the unit can supply without problems for an unlimited period of time. In the “weakest” models, this figure is
< 1 kW, in the most powerful ones –
50–100 kW and even
more ; and generators with welding capabilities (see below) usually have a nominal power from
1–2 kW to
8–10 kW.
The main rule of choice in this case is as follows: the nominal power must not be lower than the total power consumption of the entire connected load. Otherwise, the generator will simply not be able to produce enough energy, or will work with overloads. However, to determine the minimum required generator power, it is not enough to simply add up the number of watts indicated in the characteristics of each connected device - the calculation method is somewhat more complicated. Firstly, it should be taken into account that only the active power of various equipment is usually indicated in watts; in addition, many AC electrical appliances consume reactive power ("useless" power consumed by coils and capacitors when working with such power). And the actual load on the generator depends on the total power (active plus reactive), indicated in volt-amperes. There are special coefficients and formulas for its calculation.
The second nuance is related to the power su
...pply of devices in which the starting power (and, accordingly, the power consumption at the moment of switching on) is significantly higher than the nominal one - these are mainly devices with electric motors such as vacuum cleaners, refrigerators, air conditioners, power tools, etc. You can determine the starting power by multiplying the standard power by the so-called starting coefficient. For equipment of the same type, it is more or less the same - for example, 1.2 - 1.3 for most power tools, 2 for a microwave oven, 3.5 for an air conditioner, etc.; more detailed data can be found in special sources. Starting load characteristics are necessary primarily to assess the required maximum generator power (see below) - however, this power is not always given in the characteristics, often the manufacturer indicates only the nominal power of the unit. In such cases, when calculating for equipment with a starting coefficient of more than 1, it is worth using the starting power, not the nominal power.
Also note that if there are several sockets, the specific division of the total power between them may be different. This point should be clarified separately - in particular, for specific types of sockets (for more details, see "230 V sockets", "400 V sockets").Max. power
The maximum power output that the generator can provide.
This power is slightly higher than the nominal (see above), but the maximum performance mode can only be maintained for a very short time - otherwise an overload occurs. Therefore, the practical meaning of this characteristic is mainly to describe the efficiency of the generator when working with increased starting currents.
Let us recall that some types of electrical appliances consume several times more power (and, accordingly, power) at the moment of starting than in the normal mode; this is typical mainly for devices with electric motors, such as power tools, refrigerators, etc. However, increased power for such equipment is needed only for a short time, normal operation is restored in literally a few seconds. And you can estimate the starting characteristics by multiplying the nominal power by the so-called starting coefficient. For equipment of the same type, it is more or less the same (1.2 - 1.3 for most power tools, 2 for a microwave oven, 3.5 for an air conditioner, etc.); more detailed data is available in special sources.
Ideally, the maximum power of the generator should be no less than the total peak power of the connected load - that is, the starting power of equipment with a starting factor greater than 1 plus the rated power of all other equipment. This will minimize the likelihood of overloads.
Motor type
Model name of the engine installed in the generator. Knowing this name, you can, if necessary, find detailed data on the engine and clarify how it meets your requirements. In addition, model data may be needed for some specific tasks, including maintenance and repair.
Note that modern generators are often equipped with
branded engines from famous manufacturers: Honda, John Deere, Mitsubishi, Volvo, etc. Such engines are more expensive than similar units from little-known brands, but this is offset by higher quality and/or solid warranty conditions , and in many cases, the ease of finding spare parts and additional documentation (such as manuals for special maintenance and minor repairs).
Power
The operating power of the engine installed in the generator. Traditionally stated in horsepower; 1 HP approximately equal to 735 watts.
First of all, the rated power of the generator directly depends on this indicator (see above): in principle, it cannot be higher than the engine power, moreover, part of the engine power is spent on heat, friction and other losses. And the smaller the difference between these capacities, the higher the efficiency of the generator and the more economical it is. However high efficiency affects the cost, but this difference can pay off with regular use due to fuel savings.
Fuel consumption (50% load)
Fuel consumption of a petrol or diesel generator when operating at half power, and for combined models when using petrol (see “Fuel”).
Fuel consumption usually increases with load. However, generator efficiency is not always linear - fuel consumption may vary disproportionately with different loads. In this case, the approximate amount of fuel consumed by the generator when operating at half power (50% of the rated power) is given. Knowing the fuel consumption and tank capacity, you can at least estimate how long one fill-up will last.
Fuel tank volume
The volume of the fuel tank installed in the generator.
Knowing the fuel consumption (see above) and the capacity of the tank, you can calculate the operating time on one gas station (if it is not indicated in the specifications). However, a more capacious tank is also more bulky. Therefore, manufacturers choose tanks based on the general level and "voracity" of the generator — in order to provide an acceptable operating time without a significant increase in size and weight. So in general, this parameter is more of a reference than practically significant.
As for the numbers, in low-power models, tanks are installed for
5 – 10 liters, or even
less ; in heavy professional equipment, this figure can
exceed 50 liters.
Sockets 230 V
The number of 230 V sockets provided in the design of the generator, as well as the type of connectors used in such sockets.
The type of connector in this case is indicated by the maximum power that is allowed for the outlet - for example, “2 pieces for 16 A”. The most popular options for 230-volt outlets are
16 A,
32 A, and 63 A. We emphasize that amperes in this designation are not the actual power that the generator can produce, but the outlet’s own limitation; the actual power value is usually noticeably lower. Simply put, if, for example, the generator has a 32 A socket, the output power on it will not reach 32 A; and the specific number of amperes will depend on the rated and maximum power of the unit (see above). So, if for our example we take a rated power of 5 kW and a maximum of 6 kW, then to a 230 V outlet such a generator will be able to produce no more than 5 kW / 230 V = 22.7 A standard and 6 kW / 230 V = 27, 3 A at its peak. And if the power has to be divided between several outlets, then it will accordingly be even less.
As for specific types of connectors, the higher the power permissible for the outlet, the higher the requirements for its reliability and quality of protection. In light of this, as a rule, higher power outlets can be connected to lower power plugs (directly or through an adapter), but not vice versa. And if there are several sockets, by their type it i
...s possible to estimate with some certainty the distribution of the entire power of the generator between them: between two identical sockets such power is usually divided equally, and more power is allocated to an socket with a larger number of amperes and power. However, specific details on this matter should be clarified separately in each case; It's also worth considering 400V outlets, if available (see below).Protection level
The level of protection provided by the generator housing — namely, the degree of protection of the “hardware” from dust, moisture and foreign objects. It is designated by the IP standard with two numbers, one of which corresponds to protection against solid objects and dust, the second — from moisture, for example, IP24.
According to the level of dust protection (first digit) in modern generators, the following values \u200b\u200bare found:
2 — protection against objects with a diameter of more than 12.5 mm (fingers, etc.);
3 — from objects larger than 2.5 mm (most instruments);
4 — from objects more than 1 mm (almost all tools, most wires);
5 — dustproof (full protection against contact; dust can penetrate inside, but does not affect the operation of the device).
Water protection levels can be as follows:
1 — protection against vertically falling drops of water;
2 — from water drops with a deviation of up to 15 ° from the vertical axis of the device (rain);
3 — from water drops with a deviation of up to 60 ° from the vertical axis of the device (rain with wind);
4 — against splashes from any direction (rain with strong wind);
In general, for indoor use, this indicator does not play a key role, but on the street and in similar conditions (for example, at a construction site), you should make sure that the selected generator is sufficiently protected — or else take additional protection measures.
Sound level (7 m)
Sound pressure level in decibels at a distance of 7 m between the noise source and the ear of the equipment operator. Since people do not work in the immediate vicinity of the generator, the parameter will be useful for estimating the noise level at a distance. For example, current European Union regulations require that the sound power of generating sets with a power of more than 2 kW does not exceed 97 dB — at a distance of 7 m, the noise from the generator engine will correspond to a sound pressure of about 72 dB.
