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How to choose the generator for giving

How to choose power plant

Diesel, petrol or gas

Petrol generators are more compact and weigh a little less. But petrol generators with power more than 20 kVA are not issued because at increase in load of the generator, the big torque is required, and only the diesel engine can provide it.

Petrol is more fire-dangerous, fuel consumption at it is more than at the diesel and fuel is more expensive.

Diesel engines possess much higher reliability because their working capacity very strongly depends on quality of materials and assembly. You sometime saw big dump trucks or a tractor on petrol engines? Of course not. Because here not turns and power, but a torque (draft) are important that it is very important for work together with the generator.

Gas-piston or gas power plants, possess quite high reliability and an economic benefit, but they have a number of the shortcomings. The first - she demands the main gas or the liquefied (balloon) gas. The second - demand the high level of safety. Therefore most of consumers prefer to buy diesel or petrol power plants.

Loadings and power

Full capacity

the Full (seeming) capacity developed by generators conditionally is divided into components: active and jet it is also measured in VA (volt - ampere). The power factor is specified on Schild of the generator. It shows what part from the full capacity developed by the generator is made by active power.

I so turns out, the generator with full capacity of 10,0 kVA, at cos φ power factor; = 0,8, can give to the consumer the active power equal 10,0 × 0,8 = 8,0 kW.

the Active power

the simplest loadings, at them all consumed energy will be transformed to heat or light. For example: glow lamps, heaters, electric stoves, irons, etc.

If their total power makes 2 kW, for their food enough 2 kW power plant. Jet power

They are subdivided by

on inductive and capacitor. At consumers of jet power energy turns not only in heat, but also part it is spent for formation of electromagnetic fields.

is considered the Measure of jet power, so-called cos φ. For example, if cos φ it is equal to 0,8, 20% of energy it will be transformed not only to heat but also on formation of electromagnetic fields.

On devices usually specify their “thermal“ power consumption and cos φ. To count “real“ consumption it is necessary to divide power into cos φ.

for example: if on a drill 500 W and cos φ are written; = 0,6, it means that actually the tool will consume 500:0,6 = 833 W.

Types of

engines Duple

Are used only in petrol, low-power and compact power plants. In them gasoline is mixed with oil and the time between failures makes no more than 500 hours. They will be useful unless, for an outdoor recreation, as a last resort, at the small dacha where several bulbs.


Is used also on petrol and diesel engines. Most of producers in Europe and America release engines of a “professional“ class with the lower arrangement of a cam-shaft (OHV), from the recommended long operation about 8 hours daily. They are equipped with system of automatic “stop“ at oil lowering of the level. Have quite high margin of safety. Also are considered as one of the most reliable in the class (an operating time of 3 - 4000 motochas).

Actually the most reliable and unpretentious are Japanese atmospheric (without turbo-supercharging) diesel engines for industrial equipment with the lower arrangement of a cam-shaft and line, mechanical TNVD. The operating time of such diesel generators is not limited and 6000 motochasam before capital repairs.

By the way, for reference

As quantity of motochas of power plant to transfer to run kilometers for the car? Very simply, we multiply motochasa on 50 and we receive approximate run of this engine in kilometers. For example: the operating time of station made 350 motochas, 350 x 50 = 17500 km. I think that, for motorists it becomes more clear.

Period of operation

Is such parameters as fuel consumption and capacity of a tank therefore time of continuous work is defined by them (never fill a tank at the working power plant - you can spill fuel on the engine). The power plant can be completed with an additional tank. But at the same time it is necessary to remember that continuously the majority of generators can work no more than 8 - 10 hours, further it is necessary to stop it, to check oil, to allow to cool down. At such mode oil replacement is required each 50 hours.

In the mode of reserve station, during the work of 1 - 2 time a week no more than 2 hours, every 250 hours for diesel, and 150 hours is made for petrol replacement of oil and an oil filter. About what the producer specifies in the maintenance instruction of power plant. Fuel and

oil If you want

that your power plant worked longer, do not forget, we live in Russia and quality of fuel at us wishes the best. Therefore I would recommend, more often to change the fuel filter and to fill in semi-synthetic oils from the known and checked producers. to

At connection of power plant to an additional fuel tank, install the additional fuel filter a separator (a separator of water and dirt).

380 or 220?

As a rule, interests the buyer two characteristics - the power and the price of the diesel or petrol generator. It is fair when you are not interested in quality (then at once it is necessary to watch a price - a leaf).

If we the power plant for the house or object where connection single-phase gets out, then it is better to buy single-phase is the fact, but the power of single-phase generators is limited by 30 kVA and what to do then? Then you will need the three-phase generator and division of loads of three separate lines. And also system of their separation during the work from the generator and carrying out measures for alignment of loading in each of lines as three-phase generators are quite sensitive to “distortion“ of phases. I would recommend, also to install to

In three-phase networks of small power single-phase generators with system of association of phases when switching on the generator (if in this network there are no consumers 380B).

So at the household level in networks both with three-phase and with single-phase tension, is more correct and safer to use the single-phase generator (without forgetting about cable section). All works on connection of power plant to a network of power supply of your house (site) trust

only to professionals. At the wrong connection of power plant not only its exit out of operation is possible, but there can be damages of all network of your electrosupplying organization. What



Electric generators with the mixed self-excitation call synchronous and hybrid. Such generators, most often, use less fuel, it is easier in management and develop current more reliably than generators of other types.

the Synchronous generator consists of the regulator, a power source, the device on development of a direct current, the converter translating a direct current. The regulator watches that the power source was started and switched off in time and controls system in general. The compact design does synchronous generators the most adapted for use.

In comparison with asynchronous, are capable to transfer synchronous generators 3 - multiple instant overloads, and also differ in higher quality of the electric power.

the Synchronous generator can provide with the electric power all types of devices without restrictions.

In professional and stationary power plants are established only synchronous and bezshchetochny, unattended generators.

the main lack of synchronous generators is a low degree of protection against external influences such as: dust, dirt, water since the synchronous generator is cooled “stretching“ through itself air, respectively everything that is airborne can get to the generator.


Asynchronous generators are applied generally as brake mechanisms and auxiliary sources of not really big power.

the Asynchronous generator is capable to provide with the electric power only resistive devices.

At start-up performance data of the generator change: the raised starting current which is combined with power failure at turning on of inductive devices and the considerable shift of phases can damage the generator.

the Overload of these generators is inadmissible, at connection of electric motors and other devices with inductive loadings the stock on power by 3 - 3,5 times is required. When using an option of starting strengthening the stock can be reduced to 1,5 - 2 times.

Advantage of the asynchronous electric generator is the fact that in it completely there are no rotating windings and electronic details which are sensitive to external influences and are quite often subject to damages. Therefore the asynchronous generator is a little subject to wear and can serve very long.


Invertor generators, is usually petrol generators of low power. Principle of operation of the invertor generator following. Alternating current will be transformed in constant by means of the rectifier then the filtration of pulsations smoothed by capacitor filters is carried out.

after that, thanks to powerful keys on the transistors or tiristor included according to the bridge scheme is carried out formation of alternating current on loading. High quality of output parameters (that is the current) is provided not only high-quality smoothing of pulsations, but also stability of work of the control system tracing necessary output characteristics by means of chains of feedback.

all this it hardly belongs To the Chinese petrolgenerators.


Pemanentny as well as invertor generators, is generators of low power. In such generators there are no rotor windings, instead of them permanent magnets which rotating are established create in stator windings EDF (Electro Driving Force).

Costs of the

installation determination of cost of installation of the diesel generator indoors, or installation of system of autostart and switching of loading, requires departure of the expert for scoping of works on start-up - adjustment and drawing up the estimate on materials and the required works.

Petrol installations are strictly forbidden to be established to the room - it is caused by requirements fire safety.