home energy

We have long been hostages of comfort and cannot imagine ourselves without the use of electricity, wherever we are. Even in the most modest country house today they cannot do without a refrigerator and lighting fixtures. One problem: so far we can only dream of uninterrupted and high-quality power supply. Rolling blackouts, outdated networks, lack of capacity, cable theft… There are a lot of problems, and it seems that there is no one to solve them, except for the developer himself. That’s when you start to think about your own, domestic energy! Why not? The dream is quite achievable.

The objective reality is that almost all modern communications and life support systems of a country house to one degree or another depend on the power supply. Heating, water supply, sewerage, water treatment, alarm and video surveillance devices, lighting, air conditioning and ventilation, and finally, household appliances, computers and communications— all this requires an uninterrupted supply of energy. When electricity stops flowing to your site, some systems may go into emergency operation. But most of them simply refuse to function. And it’s not even about reducing the level of comfort— Expensive equipment can fail. ToFor example, a long shutdown of the boiler in winter will result in a freezing of the heating and water supply system.

Of course, ideally, it is better to plan a backup power supply system even at the stage of building or finishing a house. To ensure that the quality of the power supply when connected to the local substation is relatively high, you can at least install a stabilizer with a frequency filtering function (stabilizer-air conditioner). It will keep your network voltage 220B, and at the same time filter the electric current from high-frequency and impulse noise. The input voltage range at which domestic stabilizers operate (128-275 V) makes it possible to guarantee the normal operation of household appliances in conditions of poor-quality power supply (outside the city, one often has to deal with low voltage).

And in order for the home electrical network to gain independence from the vagaries of the local substation, you need your own backup source of electricity. Uninterruptible power supplies are unlikely to be a way out— they work as long as the capacity of the batteries used is sufficient. But what if the resumption of power supply is delayed indefinitely? Today, as a relatively reliable protection against blackouts, gasoline or diesel generator sets, or mini-power plants are widely used. Often, such equipment is acquired already during construction, if a permanent power supply line has not yet been laid to the construction site.

What it is?

The same autonomous device that generates electric current is often called differently. So in a store you might hear the words «generator system», «generator set», «generator set», «power plant» andothers inIn principle, all these names are appropriate. We will agree to call such equipment mini-power plants. This refers to a device in which the two main elements are an internal combustion engine and an electric generator. If we simplify the principle of operation of the power plant as much as possible, then it looks like this: the motor, burning fuel, rotates a shaft connected directly to the generator rotor. The generator, in turn, converts mechanical energy into electrical energy. If we do not touch on industrial designs, but talk only about relatively small-sized stations for domestic use, then, as a rule, a bunch of «engine— generator» is mounted on a solid space frame made of metal pipes, equipped with a fuel tank, a power unit starter, an oil level sensor, an hour meter, and control systems. If an electric starter engine start is provided, the station is equipped with a battery (however, for some manufacturers it is not included in the basic package and is offered additionally, for a fee).

The list of electrical equipment of the station can be quite wide. ATdepending on the model, it may include a voltmeter, an ammeter, an automatic or manual voltage regulator, a protective device against current leakage (RCD), an isometer (protective block with constant monitoring of the insulation between the mains and a protective wire), waterproof sockets, 12-volt output DC for battery charging andt.e. True, each element complicates the design of the station, which means that its final cost increases. Therefore, in most cases, manufacturers offer basic models, and additional electrical equipment can be ordered for a fee.

Most power plants are equipped with standard connectors (in other words, sockets). But if the unit is intended for permanent installation as a permanent backup power source, it makes sense to connect the electrical cables directly to the output terminals, which are usually located on the instrument panel of the generator set. ATin accordance with the international CEE standard, the sockets at the stations are color-coded depending on the voltage: yellow— 110B, blue— 230B, red— 400AT.

Mini-power plants are assembled under various brands by a fairly wide range of companies from Japan, the USA, Great Britain, Germany, Italy and Russia. Moreover, two groups of producers can be quite clearly distinguished. Some manufacture power plants based on their own engines, purchasing generators on the side (this range includes MITSUBISHI, LOMBARDINI, YANMAR). Others produce stations using generators of their own production and purchased power units. This is what F does.G.WILSON (Great Britain), METALLWARENFABRIK GEMMINGEN (Germany), MOSA (Italy), SPARKY (Bulgaria) and others. There are companies that only assemble. All the most important components (motors and generators) they receive from other manufacturers. ToFor example, from imported components, the company AMP-SET«(Moscow). There is no reason to be suspicious of certain manufacturers, as well as to firms engaged only in assembly: all three approaches all over the world— business usual. Why waste energy on developing your own components when you can take the most reliable components from a specialized company and thereby reduce the cost of the station?

When it comes to gasoline engines, power plants are equipped with power units from manufacturers such as KUBOTA, MITSUBISHI, ROBIN, HONDA, YAMAHA, SUZUKI (Japan), BRIGGS STRATTON (USA), LOMBARDINI, TECUMSEH (Italy). Diesel engines are manufactured by the already named HONDA, TECUMSEH, ROBIN, YAMAHA, KUBOTA, as well as YANMAR (Japan), ACME, IVECO, RUGGERINI (Italy), HATZ, DEUTZ (Germany), etc. Most often, stations are equipped with electric generators from METALLWARENFABRIK GEMMINGEN (trademark Geko), GENERAC, STANFORD (Great Britain), LEROY SOMMER (France), YAMAHA, SAWAFUJI ELECTRIC (Japan), SINCRO (Italy), etc.

Our market includes power plants manufactured by Japanese companies ROBIN (a division of FUJI HEAVY INDUSTRIES), SAWAFUJI ELECTRIC (trademark Energo), HONDA, KUBOTA, YAMAHA, German METALLWARENFABRIK GEMMINGEN, ENDRESS, French SDMO and WORMS, as well as MOSA, SPARKY, F .G.WILSON and others. The METALLWARENFABRIK GEMMINGEN factory has two divisions and two trademarks: under the Geko brand, mainly asynchronous stations are produced, and under the Eisemann brand— with synchronous generators.

Power selection

Of course, the main criterion for choosing a power plant— its power, which must correspond to the power of the powered equipment. AtFor many owners of country houses, the list of consumers connected to the backup power supply may be the same, but the technical characteristics of these systems, their combination and mode of operation are likely to be different. Take at least the last factor, which is determined by the frequency and duration of outages, lifestyle and the number of inhabitants of the house.

Therefore, it is very important to decide what exactly you want to connect to the power plant, and calculate the total power, taking into account the starting power of certain electrical appliances and the switching-on simultaneity factor. Particular attention should be paid to consumers with increased sensitivity to power quality, such as computer equipment, hi-end equipment, measuring instruments, etc.

This is the time to think about which devices and systems in the house really need to be powered in the first place. The point is that the power plantThe equipment is relatively expensive. And the electricity that it generates is not cheap: if you take into account the cost of fuel,kWh home electricity is about four times more expensive than the «grid», from the local distribution system. Therefore, a complete transition to «own» electricity is not economically feasible. It is more reasonable to divide all consumers into several categories. Thus, among the least responsible are devices and systems that you can do without if the power is turned off, for example, saunas, showers, cable floor heating systems andt.e. The second category will be consumers who provide comfortable living. This includes, say, kitchen appliances (stove, refrigerator, kettle, dishwasher), televisions, audio and video equipment, irons, electric shavers, and finally, computers. Third category— the most important, since it contains life support systems (emergency lighting, security and fire alarms, video surveillance devices, electric locks, heating and water supply).

Obviously, consumers of the first category should work only when the main power supply is in operation. It makes no sense to reserve any capacity for them because of the unfavorable «need-to-cost» ratio. BUTit makes sense to power the most necessary electrical appliances and life support systems from a backup source. As practice shows, most often the list includes boiler room equipment, a burglar alarm, a water pump, a TV and a refrigerator, several lighting lamps and heating appliances. As a rule, their total power is about 5kW, but with a strong desire, you can reduce your own needs by half, up to 3kW.

There are a significant number of consumers of electricity, immediately at the time of launch of which the starting power can exceed the rated power by 2-3 times. Large starting currents (and hence high power consumption) in the on mode are typical for devices with asynchronous electric motors. Let’s say the average power rating of a refrigerator compressor motor is— 0.2kW, and at the time of launch it will need about 1kW. The power of a submersible pump can be, for example, only 1kW, and the amount of power at the time of start, due to the large starting current, can be 5 times greater. So, if you do not take into account starting loads, either the generator or the electric motor will burn out. Almost all manufacturers equip power plants with overload protection by installing a temperature sensor on the stator windings of the generator. This is how the Elemax SX-DX series (a joint development of the Japanese SAWAFUJI and the Russian NPO ENERGOSPETSTEKHNIKA), the EX series from HONDA, the RGV family of stations from ROBIN, etc. (if you, for example, are trying to remove 5kW from a station with a capacity of 4kW), the temperature controller switches off the unit.

Experts believe that the power plant should operate «with a margin», at 80-90% of the installed rated capacity. This is the most efficient mode in terms of stability, service life and economic efficiency. That’s just the power of the stations themselves, manufacturers indicate in different ways. ATtechnical documentation for European units, as a rule, the rated power is prescribed. ATIn this case, you can connect only the equipment, the power of which in the starting modes does not exceed the total rated power of the power plant. Almost any Japanese unit has two characteristics— rated and maximum power. At nominal, the station operates indefinitely until refueling or oil change is required. The difference between the maximum specified by the manufacturer and the rated power is the power reserve required to provide starting currents for a short period of time. ATrange from nominal to maximum, the station can operate within 5-10, maximum 20-30 minutes, after which the thermal protection is activated, turning off the unit. The continuous load mode is designed to operate at 80% of the rated power. ATIn this case, connect as many devices as possible so that the total starting power does not exceed the maximum power of the station.

About generators

When choosing a power plant, you should pay attention to which generator the installation is equipped with.— synchronous or asynchronous. The synchronous type generator produces stable voltage and frequency parameters. A station with such a generator is good for stationary use, withstands high starting currents, it can be loaded at full power by connecting various power tools that are not too demanding on the quality of the current, as well as household appliances (pumps, refrigerators, washing machines, etc.). ATRecently, brushless synchronous type generators have been used in the design of power plants, which do not need maintenance.

Asynchronous generators produce the purest sinusoid, but overloading with starting currents in this case is highly undesirable. It is best to connect equipment sensitive to voltage drops to stations with an «asynchronous»— electronic devices, computers, tape recorders, CD players, etc.if the station is used to power incandescent lamps, electric heaters, or if the power of connected electric motors and other inductive loads is 3-4 times less than the power of the generator, it is also better to use «asynchronous».

Power plants can use single-phase or three-phase generators. The former give out alternating current with a voltage of 220 V and a frequency of 50 Hz, the latter are designed for both 220 and 380B. Moreover, if only single-phase loads can be connected to single-phase generators, then three-phase ones can provide energy for devices designed for both 220 and 380 V. If you are going to purchase a power plant with a single-phase generator, it is enough to calculate the necessary consumers without errors (taking into account their starting currents) and pay for a unit with a suitable power output (adding 25-30% for margin).

As for three-phase generators, when connecting single-phase consumers to them, a phase imbalance problem may arise: one of them will be loaded less, the other— more. Firstly, the phase imbalance (that is, the difference in power of consumers connected to them) at a station with a synchronous generator should not exceed 1/3, or 30%. If, for example, your three-phase unit has a capacity of 6kW, the total power of single-phase consumers should not exceed 2kW per phase. If you also connect a heater, at least 1.5kW, there is a possibility that the generator will burn out. Secondly, even if your house has a three-phase network, backup power supply can technically be arranged in single-phase mode. You just have to calculate which of the phases of the generator is loaded more, and which— less to avoid distortion. Well, when there are permanent three-phase consumers in the house, for example, a deep pump is running, the choice falls on a three-phase asynchronous generator (installed, for example, on models such as Geko 6000 Ed-A / HHDA, ESE 204 from ENDRESS or a series of GE stations from MOSA). It withstands phase imbalance up to 80%.

Motor!

Mini-power plants are equipped with internal combustion engineseither petrol or diesel. Units with a gasoline engine are produced in the power range 0.5-12kW, with diesel— from 2kW and above. So the problem of which engine to choose only arises if you need a station with a power of 2 to 12kW: units over 12kW are produced, as a rule, with a diesel engine.

In comparison with diesel engines, gasoline units, in addition to lightness and compactness, are less noisy and less vibration-loaded, and with the same dimensions and weight— more powerful. Most small stations (up to 6kW) and medium (up to 12kW) power, and practically only four-stroke engines with overhead valves are used. This arrangement allows to reduce the surface area of ​​the combustion chamber (and, accordingly, reduce the heating of the assembly itself) and increase the compression ratio, thereby increasing the efficiency of fuel combustion. Such units are marked OHV (the most famous products are from HONDA, BRIGGS STRATTON, YAMAHA, SUZUKI). All modern engines are already equipped with oil level sensors as standard, and if the oil level in the crankcase is below normal, the system forcibly turns off the engine.

Petrol stations with a capacity of 6-7kW are most often equipped with a single-cylinder, four-stroke, air-cooled engine and have an open frame design. These are, for example, a portable single-phase electrical unit EF-4600E from YAMAHA, «giving out» alternating current 15.9A, or model EP3000 from HONDA (220VAC 9BUT). The interval between maintenance for engines from HONDA is 100h, maintenance is reduced to changing the oil. Fuel— ordinary automobile gasoline of the brand AI-92 or AI-95 (mainly AI-92). The oil is used semi-synthetic or mineral.

To start a cold gasoline engine, you will have to cover the air damper and, as the engine warms up, open it. Of course, manual start can be facilitated. So, on motors from HONDA, a system is used that, at the moment the lace is pulled, slightly opens the valves to ease the effort. But what if you live in the house periodically or at the time of the network outage, only elderly people and small children are present in it? In this case, it makes sense to equip the station with an electric starter or also purchase an external manual remote control. Just check with the seller if the model you have chosen allows the installation of an electric starter and remote start using a remote control connected to the station by a cable.

A station with a gasoline engine is worth purchasing if it does not need to be turned on too often and for a long time and you need relatively small power (5-6kW). This is a good option for a compact «emergency» or seasonal (say, for a country house) power source. Or suppose you have no light for a maximum of two weeks a year. It is simply not economically profitable to buy a diesel engine: the most expensive gasoline models cost no more than $900, while the cheapest diesel (from 2kW) will cost $1400-1500. In fact, the cost of gasoline and diesel engines of the same power differs by 2 times.

As soon as you expect that the station will be operated quite often or serve as a constant source of electricity, or, finally, you need a large (over 10kW) power, the choice in favor of a diesel engine is obvious. Diesel units are more economical than gasoline units. ATFirst of all, this means low fuel consumption, which means lower costs for the purchase of diesel fuel. That is why, in fact, the stations are more powerful than 12kW and are represented only by diesel models. In addition, the upper limit of their power is not limited, and the power of gasoline units does not exceed 9-12kW. And one more thing: compared to gasoline, diesel fuel is less flammable and can be more convenient to use. But you need to remember to switch to winter grades of fuel in time: at a temperature of about-fifteenSummer fuel saturated with various impurities crystallizes, becoming more viscous. Another important argument in favor of diesels— a greater resource of work (when compared with gasoline modifications). ATon average, it is about 8 thousand hours.

Diesel power plants differ in the method of cooling: air ones are cooled by air inflow, and liquid ones use antifreeze as a coolant. Liquid-cooled diesel engines are mainly used in stationary power plants, for example in ENDRESS ESE family units, in HONDA EXT 12D models, Energo SHT 15D by SAWAFUJI, GL6500S from KUBOTA andetc. As a rule, the radiator in them is installed in a noise-protective casing, where it is impossible to provide sufficiently effective air cooling. In portable and portable stations (for example, Typ 15000 from GEKO, EDA 5000 TE from YAMAHA, the entire ROBIN line), the diesel is air-cooled, which significantly reduces the cost of equipment.

Diesel engines can also be started-25C. Air heating is available for easier starting— the intake manifold is equipped with an electric heater (this option is offered for a fee). But with sudden temperature changes, moisture vapor condenses, which can adversely affect the electronic components of a diesel power plant (electric starter, control circuits, generator). Therefore, the passport operating temperature of power plants (for example, the French SDMO)-5C. So you have to think about providing heating for the room where the station is being installed.

Automation

So, you have decided which electrical appliances will need to be powered from a backup power source. Toeach of them needs to stretch a separate wiring from the power plant (without serial connections). So you get a redundant network. And you won’t have to run around the rooms, turning off electrical appliances one by one, when the lights are turned off, before starting the mini power plant. After all, it is enough to forget to turn off the stove or refrigerator once, and the generator (if it is not designed for such additional loads) will burn out. The arrangement of a separate electrical circuit is best provided for at the design and construction stage. If you buy a station in a ready-made house, the wires can be routed through cable channels.

But how to switch between a regular home and backup networks? To do this, you can use special manual or automatic devices.

In the first case, a so-called changeover switch should be installed in the house, which has two independent positions: “from the network” and “from the station” with a mechanical interlock that prevents the simultaneous, oncoming switching on of both energy sources.

Imagine that you have all the lights, TV, electric stove, audio equipment turned on and the submersible pump is working. And suddenly the centralized power supply stops. You go down to the basement, start the power plant and connect to the reserved home network. After a while, they give light again, and if you stop the electric unit for joy, but do not disconnect the station from the network, the generator simply burns out. This will not happen if a toggle switch is installed in the house.

In order not to suffer with a manual start, buy an electric starter for the station ($50-150). ATIn this case, the station will start at the touch of a button. You can also purchase a remote wired control panel (its cost varies with different manufacturers from $200 to $350)— provided that the design uses not a mechanical, but an electric starter.

But there are devices that allow the station to turn on automatically, without your participation. Electronics monitors the state of the main power supply network and independently starts the station in the event of a power failure or sag in at least one of the phases. When stationary power is restored, the load switches back, while the station itself goes into standby mode. The minimum time without voltage between the loss of voltage in the main network and the restoration of power to the load from the generator is from 20 to 50 seconds for different manufacturers.

The least troublesome solution to the problem of automated control of the backup network is to opt for stations with electronics. It is available, for example, in single-phase models ESE804BS/S ES (petrol synchronous unit; $2760) from ENDRESS, «Energo» EA7000A (petrol synchronous; $2950) from SAWAFUJI / «ENERGOSPETSTEKHNIKA», «Vepr» ABP-6-230-VKhBSG (petrol synchronous; $3100) from «AMP- SET«, Eisemann Р700УBLC (petrol synchronous; $3770), etc.

For ESE804BS/S ES and «Vepr» ABP-6-230-VKhBSG stations, the switching and control electronics unit is mounted separately, in its own housing, next to the electrical distribution board. The control cabinet and the station are connected to each other by a signal loop and a power cable. Automation monitors the reduction (usually to the level of 150 V) or loss of voltage and decides on the transfer of reserved electricity consumers to autonomous power. The remaining stations from the above have built-in electronics. Let’s say, to the input terminals of the model «Energo» EA7000A (rated power 5kW) it is enough to connect the «zero» and «phase» of the external power supply (the installation case is grounded), and the internal home network can be considered to be reserved. When the external network is working, the power supply of consumers is switched to it— the station passes current «through itself». As soon as a failure occurs (voltage drops, rises or disappears), the station starts up on its own. When the stationary power supply is restored, the unit switches to an external source. ATin this mode, the power plant will work until the tank runs out of fuel. It will only be necessary to periodically add gasoline.

Automatic control cabinets, switching units (programmable controller, power contactors, RCD devices andt.e.) are mounted near the electrical panel. Carrying out all the necessary installation and electrical work can be entrusted to large sales companies that have their own service department (such, for example, as AOYAMA MOTORS, AMP-SET«, «ENERGOSPETSTEKHNIKA», «EKONIKA-TECHNO»). For small stations, the automatic start block in case of loss of load in the main network costs up to $600, and for powerful units it will cost $1500-1900 and more (taking into account the complexity of the work). The cost of the node also depends on the power of the loads. For example, for the EAS 5/5D automation cabinet from MOSA, designed for 3.6 and 5kW, ask 900, and for the EAS 22/40 model (from 8kW)— already 1900. Domestically assembled autonomous control system (using imported components) will cost $1500-3000, including the cost of installation.

What else to pay for?

Like any unit with an internal combustion engine, the power plant is noisy. And the stronger, the less comfortable you feel. continuous noise— the phenomenon is unpleasant, therefore it is important to provide certain measures of protection against it. What can be done? In addition to the fact that the station is best placed in a special room (basement or outbuilding not far from home), it would be nice to choose a model with a modified muffler or in a noise-protective casing. The latter will increase the cost of the station by $800-1000. ATJustifying the relatively high price, we can say that the casing is not just a metal cap, but a well-thought-out design in which the manufacturer took into account the problems of cooling, exhaust gas removal, sound insulation, layout of components (for example, the location of the tank and its neck), etc.

The time of continuous operation of the station without refueling is determined by the volume of the fuel tank and fuel consumption. Tofor example, in small stations with a good motor tank capacity of 6.5l is enough for 3-3.5 hours of operation when loaded at rated power. Large capacity tank (say 25l) will allow you to work on one gas station for 9-10 hours. It is possible, having bought a standard model, to subsequently purchase an increased tank or immediately stop at a station with a large tank. Please note that the fuel consumption indicated by the manufacturer is relative: when operating at different loads from the rated power, the indicators can vary significantly. For a large stationary generating set, used only as a backup power source, it is of course possible to purchase an external fuel tank in order not to constantly top up the fuel. But is it nice to “sit on a barrel of gasoline”, and where to store its reserves? Perhaps it is better to periodically add fuel to the tank. It’s easier with a diesel. It is often bought if the boiler room runs on diesel fuel and there is already a place to store fuel.

Save fuel (up to 25%) and reduce noise (by 5-6db) allows electronic speed control. Under load, the station engine rotates at a nominal frequency of 3000 rpm, and when electrical consumers are turned off, it switches to idle. Switching on consumers again leads to an instantaneous increase in the number of revolutions to the nominal one. Such blocks are installed on a number of models from HONDA, SAWAFUJI, ROBIN, at the Geko station from METALLWARENFABRIK GEMMINGEN (in this case they are called Geko Silent Economic). The system of automatic control of the engine speed increases the cost of the power plant by about 10-15% (for different manufacturers).

For installation and connection of the power plant, you should use the services of a specialist. The price of such services is approximately 10% of the order value (if you purchase everything you need «from one source»).

Finally, a few recommendations for the placement of the power plant. It must be installed on a level surface, in a separate room, protected from moisture, away from flammable materials and well ventilated. Installing a power plant in a boiler room is prohibited by both gas workers and firefighters. As an option— you can order a prefabricated mini-container with a heating system in winter, fire extinguishing and ventilation systems. The cost of domestic samples— from $1000. The disadvantage of such a solution is that not everyone will dare to spoil the view of the site with an “iron box”.

So, if you decide to make your home a territory independent of the whims of the local power grid, your dream may well become a reality. And you don’t have to dine by candlelight. At least forced.

The editors are grateful for the help in preparing the material to the companies AOYAMA MOTORS, ECONICA-TECHNO, ENERGOSPETSTEKHNIKA

• Source: Ideas for Your Home Magazine#71