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.
Alternator winding
—
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.
Engine size
The working volume of the engine in a gasoline or diesel generator (see "Fuel"). Theoretically, more volume usually means more power, but in fact, everything is not so clear. Firstly, the specific power strongly depends on the type of fuel, and in gasoline units, also on the type of internal combustion engine (see above). Secondly, similar engines of the same power can have different volumes, and there is a practical point here: with the same power, a larger engine consumes more fuel, but by itself it can cost less.
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.
Output 12 V
Existence in the generator of an
output with a direct current and voltage of 12 V. The main function of this output is to charge car batteries, as well as power devices originally intended for cars (recall, 12 V is the standard voltage of on-board networks in cars).
The following types of 12-volt outputs are found in generators:
- Terminals. Terminals are used to connect wires directly without using any plugs. This connection is the most reliable.
- Socket. Socket outlet for a plug with two flat pins, designed to connect 12-volt consumers. Holes in sockets come in different layouts, which you need to pay attention to.
- Cigarette lighter. The so-called "car socket", which in many cars is combined with a cigarette lighter socket (hence the name). Such connectors are used to power various automotive devices and accessories.
Features
—
12V output. The presence of an output with direct power and voltage of 12 V in the generator. The main purpose of this output is to charge car batteries, as well as to power devices originally intended for cars (recall that 12 V is the standard voltage of on-board networks in passenger cars).
—
USB charging port . The presence of a USB connector (one or more) on the generator for charging various devices. Most modern smartphones and tablets can be charged via USB, and this charging method is also found in many other devices — from cameras and flashlights to electric screwdrivers and radio-controlled models. The standard supply voltage through this connector is 5 V, but the power may be different, it should be specified separately.
—
Smartphone control. Synchronization with a smartphone allows you to control the generator remotely. Thanks to this, the user does not need to approach the device to, for example, start or stop it. Additionally, synchronization with a smartphone allows you to monitor the parameters of the generated electric power remotely and in real time. On the other hand, this will require a constant connection to the Internet and specialized software that must be installed on the smartphone.
—
Autostart (ATS). A function that allows the generator to turn on automatically under certain conditio
...ns, without any action from the user. Autostart is mainly used when using the generator as a backup power source: while the main power is working, the unit is turned off, and if the voltage in the network disappears, ATS starts the engine, and power to the load begins to flow from the generator. Note that the presence of autostart is indicated only if the generator is initially equipped with an ATS electronic unit; models with the ability to connect such a unit are placed in a separate category (see below).
— ATS socket. A connector that allows you to connect an external autostart unit (ATS) to the generator; the unit itself is not included in the kit. For more information on autostart, see above; here we note that some users do not initially need this function, but may need it in the future — for example, if the generator is initially used for building a house, and then it is planned to be installed in the same house as a backup power source. In such situations, this configuration option will be optimal: when buying the generator itself, you will not have to overpay for the ATS unit, and later, if necessary, you can buy and connect such a unit separately.
— Automatic voltage regulator (AVR). An automatic regulator that allows maintaining a constant voltage level at the generator output. Such a regulator smooths out the differences that occur due to changes in the engine speed; this is especially important when connecting devices that are sensitive to power supply stability. It is worth noting that the presence of an AVR is almost mandatory for synchronous generators (see "Alternator"), but in other varieties this function is not found: in asynchronous and duplex units it is not applicable in principle, and in inverter units the role of the regulator is played by the inverter itself, and they do not require additional electronics.
— Display. A dedicated display mounted on the generator body. Typically, this is a simple LCD screen capable of displaying only numbers and some special symbols. However, even such a screen can display various useful information: voltage, frequency, engine hour meter data, low fuel warning, error code failure messages, etc. This makes control more convenient and visual.
— Hour metre. A device that counts the total time that the generator engine has been running since it was first turned on. This helps determine the overall wear of the engine and the need for repair/replacement, which can be useful both during long-term use of the device and, for example, to assess the quality of the product when buying a used generator. It is usually impossible to reset the hour meter without serious intervention in the design of the device.
— Voltmeter. A device that displays the power voltage produced by the generator. The voltmeter can be made in the form of a separate pointer scale, or its readings can be displayed on the generator's own display (see above). In any case, this function allows you to carefully monitor the unit's operating mode and reduces the risk that an unacceptable voltage will be applied to the load.
— Parallel connection. The presence of special connectors in the generator design, through which two or more units can be connected to a single electrical network (usually with the help of an additional device). This type of connection is used when one unit is not able to handle the entire load and the connection power exceeds the capabilities of the device itself. Also, such a scheme has gained popularity if one of the units is planned to be used as a backup power source.
— Remote start. The remote control generator is included in the delivery set. It is made in the form of a wireless key fob and allows you to turn on/off the device remotely without approaching it.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.