Comparison Elprom EBG 2500 vs Forte FG 2000

The rated power of the generator is the highest power supply that the unit is capable of delivering without problems for an unlimited time. In the “weakest” models this figure is less than 1 kW, in the most powerful – 50 – 100 kW or even more ; and generators with welding capabilities (see below) typically have power ratings ranging from 1 – 2 kW to 8 – 10 kW.

The main rule of choice in this case is this: the rated power must not be lower than the total power consumption of the entire connected load. Otherwise, the generator simply will not be able to produce a sufficient amount of energy, or it 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, you need to take into account that only the active power of various equipment is usually indicated in watts; In addition, many AC electrical appliances consume reactive power (the "waste" power consumed by coils and capacitors when operating at that power). And the actual load on the generator depends precisely 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 supply of devices in which the starting power (and, accordingly, the power consumption at the moment of switching on) is significantly higher than the rated 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 one type of equipment it is more or less the same - for example, 1.2 - 1.3 for most power tools, 2 for a microwave, 3.5 for an air conditioner, etc.; More detailed data is available in special sources. Starting characteristics of the load are necessary, first of all, to assess the required maximum power of the generator (see below) - however, this power is not always given in the characteristics; often the manufacturer indicates only the rated 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, and not the rated power.

Also note that if there are several outlets, the specific division of the total power among 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”).

The maximum power supply that the generator can provide.

This power is slightly higher than the rated power (see above), but the maximum performance mode can only be maintained for a very short time - otherwise overload occurs. Therefore, the practical meaning of this characteristic is mainly to describe the efficiency of the generator when operating with increased starting currents.

Let us remind you that some types of electrical appliances at the moment of startup consume many times more power (and, accordingly, power) than in 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 just a few seconds. And you can evaluate the starting characteristics by multiplying the rated power by the so-called starting coefficient. For one type of equipment it is more or less the same (1.2 - 1.3 for most power tools, 2 for a microwave, 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 lower than the total peak power of the connected load - that is, the starting power of equipment with a starting factor above 1 plus the rated power of all other equipment. This will minimize the likelihood of overloads.

The type of alternator provided in the unit.

The alternator is the part of the generator that is directly responsible for generating electricity. Such a system works on the principle of the movement of wires (coils) in a magnetic field, due to which an electric current arises. However, the features of the work of the alternator can be different, on the basis of which they are divided into types: asynchronous , synchronous, inverter and duplexes. Here are the main features of each option:

— Asynchronous. The simplest version of the alternator. The rotor (rotating part) in such models during rotation is somewhat ahead of the movement of the magnetic field created by the stator (fixed part) — hence the name. The practical advantages of asynchronous alternators are simplicity, low cost, good protection from external influences and insensitivity to short circuits and prolonged overloads. The latter makes them the best choice for powering welding machines. In general, asynchronous generators are designed mainly for active loads: lighting devices, computers, electric heaters, etc. For reactive loads (with coils and capacitors), it is better to use synchronous units (see below). It is also worth noting that in an asynchronous alternator, the voltage and frequency of the output current directly depend on the rotation speed; t...herefore, such devices are particularly demanding on the stability of the drive motor.

— Synchronous. In this type of alternators, the rotation of the rotor and the magnetic field of the stator coincide (unlike asynchronous models). Synchronous generators are somewhat more complex in design and more expensive, they are more sensitive to short circuits and prolonged overloads. On the other hand, such a unit does an excellent job with both resistive and reactive loads: for a short time, it is able to deliver a current many times higher than the rated current, thus providing the necessary starting current for the reactive load. In addition, the design of synchronous generators includes an automatic control unit that outputs a stable voltage and is able to compensate to a certain extent for fluctuations in the speed of the drive motor. However, in terms of voltage stability, synchronous models are still inferior to inverter ones (see below).

— Inverter. Synchronous generator (see above), equipped with an additional electronic unit — an inverter. This block provides double current conversion: from AC to DC and then back to AC. Such devices are not cheap, but they have a number of advantages. Firstly, the output is a very stable current, practically without any jumps and fluctuations. Secondly, the generator is able to regulate the operation of the engine depending on the load: for example, if the load is half of the output power, then the current engine power is halved; this results in significant fuel savings. Thirdly, inverter models are lighter and more compact than traditional generators, and they are less noisy. It is such a generator that is considered the best choice for a load that is sensitive to the quality of the current, such as audio equipment or a TV. At the same time, units of this type have a relatively low power and are not designed for long-term operation or high starting loads, and therefore they are used only as backup power sources for relatively low-power power supply systems. In addition, when choosing an inverter generator, it is worth clarifying the shape of the output signal: not all models give an perfect sine wave — there are also units with a trapezoidal pulse that are not suitable for delicate equipment.

— duplex. Type of alternators developed by Endress and used mainly in generators of this brand (although devices from other manufacturers are also found). According to the creators, such an alternator combines the advantages of synchronous and asynchronous models. So, on the one hand, it is able to withstand high inrush currents without compromising the supply of other consumers, and the design usually has an auto-voltage regulator at the output; on the other hand, most of these generators can also be used to power welding machines, and the number of high-frequency harmonics at the output is very low. The disadvantages of "duplexes", in addition to the high cost, include the need to configure for a specific set of connected devices.

— Copper. Copper winding is typical for advanced class generators. The copper alternator is characterized by high conductivity and low resistance. The conductivity of copper is 1.7 times higher than the conductivity of aluminium, such a winding heats up less, and compounds made of this metal endure temperature drops and vibration loads. Among the disadvantages of the copper winding, one can only note the high cost of the alternator. Otherwise, generators with copper winding have high reliability and durability.

— Aluminium. The aluminium winding of the alternator is typical for low-cost-class generators. The main advantages of aluminium are light weight and low price; otherwise, such a winding is usually inferior to copper counterparts. An oxide film is created on the surface of aluminium, it appears everywhere, even in the places of contact soldering. The oxide film undermines the contacts and does not allow the outer protective braid to securely hold the aluminium conductors.

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.

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.

A pointer that allows you to monitor the remaining fuel in the generator tank. The simplest such indicators work only with a critical decrease in the level of fuel, warning of the need for refueling; more advanced ones constantly display the remainder. However, anyway, this feature makes it easier to keep track of the fuel supply and reduces the risk of a generator shutdown due to a forgotten refueling.

The time during which the generator is guaranteed to operate without interruption.

This parameter is indicated exclusively for liquid fuel models with a built-in tank, and according to the simplest formula: tank capacity divided by fuel consumption. However, in some models, data may be provided for a certain load level (which is specified in the notes); at a higher or lower load, the operating time will be shorter or longer, respectively. As for specific numbers, in most modern generators the operating time is up to 8 hours - this is quite enough for backup power and occasional use. More reputable models are capable of working for 8 – 12 hours, and an indicator of 13 hours and above is typical mainly for professional solutions.

We also note that, theoretically, many generators can be refueled without shutting down, but in practice it is better to take breaks and not exceed the stated time of continuous operation - this will avoid overheating and increased wear.

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 current that is allowed for the outlet — for example, "2 pcs at 16 A". The most popular options for 220-volt outlets are 16 A, 32 A and 63 A. We emphasize that the amperes in this designation are not the actual current that the generator can produce, but the outlet's own limitation; the actual value of the current strength is usually noticeably lower. Simply put, if, for example, the generator has a 32 A socket, the output current 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 such a generator can deliver less than 5 kW / 230 V = 22.7 A nominally and 6 kW / 230 V = 27 to a 230 V socket, 3 And at the peak. And if the power has to be divided between several outlets, then it, accordingly, will be even less.

As for specific types of connectors, the higher the current allowed for the outlet, the higher the requirements for its reliability and quality of protection. Thus, usually, smaller power plugs can be connected to higher power sockets (directly or through an adapter), but not vice versa. And if there are several sockets, by their type it is pos...sible to estimate with a certain certainty the distribution of the entire power of the generator between them: between two identical sockets, this power is usually divided equally, and more power is allocated to the socket for a larger number of amperes. However, specific details on this matter should be clarified in each case separately; also consider 400 V sockets, if available (see below).