How to extend the life of a generator - rules for operating power plants that extend their service life

It is almost impossible to ensure uninterrupted supply to a residential building, commercial enterprise or municipal institution using only public utilities. There is always the possibility of emergency situations that can disable the network or expensive equipment for hours or even days.

A backup generator will guarantee the necessary uninterrupted power supply in any situation, both for an individual home and for any commercial facility, including industrial complexes, where every minute of downtime is accompanied by loss of money, and in some cases can even cost a person’s life.

When deciding to purchase a mini-power plant, you need to pay attention not only to the cost of the equipment, but also to its performance characteristics, which should best correspond to the specifics of consumers, the level of required power and other equally important parameters. Let's consider the key aspects of choosing backup generators in detail.

What is a backup generator

An auxiliary mini-power plant implies an automated complex that provides temporary power supply to objects or hotel equipment in the event of interruptions in the supply of electricity from main sources. They are also required in cases where the quality of the main energy does not meet the indicators necessary for operation. The control units activate the installation and regulate the voltage, and also automatically turn off the backup source after the central power supply is restored.

How to choose and what to pay attention to?

The selection criteria are as follows:

1. Pay attention to the engine type . Power units from the Honda GX family have gained popularity. They are distinguished by an increased service life, simple design, functionality, and affordable price.
2. Availability of protection . The model must have an oil level sensor, automatic shutdown if there is insufficient amount of lubricant. Overheating protection will be a big plus.
3. Launch method . Gasoline generators are equipped with an electric starter, an automation unit, and a manual start type. The buyer decides which type to choose based on personal preferences and financial capabilities.
4. Generator type . It is better to choose a brushed gas generator. It does not require regular replacement of brushes and is designed to work with various power tools, household appliances and welding machines.

How does a backup generator work?

The backup generator operates completely autonomously in the same way as standard power plants. For its operation, a certain amount of fuel (depending on power) and the presence of control equipment are required. The latter will ensure the start of the power unit and control of parameters by reading the characteristics of the central network. In this case, the auxiliary mini-power station can be turned on manually. The method of its input and output from the network depends on the specification of the serviced object and the preferences of the owner.

The most efficient and versatile are power plants equipped with internal combustion engines (internal combustion engines). Their popularity is due to the ability to work in any conditions, regardless of temperature, humidity and other external factors. The operating principle of such backup generators is very simple: as a result of combustion of the fuel-air mixture inside the engine cylinders, the crankshaft rotates. From it, mechanical energy is transferred to the generator, where it is then converted into electrical current.

Car device

Page 1 of 5

Generator malfunctions have the following main symptoms: no charging current when the engine is running, reduced charging current that does not provide the necessary charge to the battery, increased charging current. The absence of charging current from the generator when the engine is running is determined by control instruments (control lamp, ammeter, voltmeter) and can be caused by failure of the generator drive belt, malfunction of the generator itself (failure of its brush assembly, contamination of slip rings, short circuit or breakage of electrical circuits generator elements), as well as a malfunction of the battery charging circuit.

It is advisable to determine the reason for the lack of charging current in the generator in the following order. First you need to check the condition and tension of the generator drive belt (see “Repair and maintenance of the cooling system”). Then you should check the regulated voltage of the generator with a voltmeter or probe with the additional resistances turned off. To do this, the voltmeter is connected to terminal “30” (or “+”) of the generator and to “ground”, observing the polarity, the average engine speed is set (approximately 2000 rpm) and the main consumers of electricity are turned on (high beam headlights, heater , parking lights). In this case, the voltage value should be within 13.7 ... 14.5 V.

If the regulated voltage of the generator is within the specified limits, then the generator is working and you need to check the battery charging circuit. Otherwise, it is necessary to remove the brush assembly with the voltage regulator, check the condition of the brushes (their wear, absence of jamming in the brush holder) and the absence of contamination of the contact rings of the generator armature, as well as the reliability of the contacts of the voltage regulator and measure the voltage again. If this does not produce results, then replace the voltage regulator with a known good one. If after replacing the regulator the voltage is not restored, then the generator should be removed from the car for a more detailed check and replacement of failed elements.

A reduced charging current manifests itself in an undercharge of the car’s battery, which reduces the intensity of the lighting fixtures and changes the timbre of the sound signal. The reasons for the reduced charging current may be slipping of the generator drive belt, malfunction of the brush-commutator assembly (contamination of the commutator, wear or jamming of the brushes), a break and interturn short circuit or a break in one of the phases of the stator winding, damage to one of the diodes of the rectifier unit.

To identify and eliminate the malfunction, you need to check the tension of the generator drive belt, the reliability of the wire contacts, remove the brush assembly and check for contamination of the slip rings, wear and absence of jamming of the brushes. If, after the measures taken, the regulated voltage of the generator is not restored, then the generator must be removed from the vehicle to check and replace the failed elements.

The increased strength of the charging current causes the battery to be overcharged, while the arrows of the control instruments (ammeter, volts) at high engine speeds, and the electrolyte “boils” and splashes out of the batteries. The cause may be a malfunction of the voltage regulator or battery. In this case, you should check the regulated voltage generator, as described above, and replace the faulty voltage regulator or failed battery.

• To the begining
• Back
• 1
• Forward
• In the end

Selecting a generator based on the type of fuel used

The type of fuel used for a mini-power plant plays a critical role. It determines the efficiency of operation under certain conditions, the cost of maintenance, financial costs of operation and other characteristics. Modern power plants according to this parameter are divided into three groups:

• Gas mini-power plants are most often used as the main source of electricity in cogeneration and trigeneration systems, where thermal energy, a by-product of electricity generation, is used for heating or cooling of premises. Such complexes are distinguished by the longest engine life, impressive dimensions, significant productivity and high cost.
• Diesel backup generators are the optimal solution in terms of performance/reliability/cost. They represent a wide group of installations with a power of 4–3000 kW and more, which stands out for its high efficiency indicators and long service intervals. The absence of the need to regulate the fuel supply when starting a mini-power plant eliminates all the negative aspects inherent in gasoline engines: increased consumption, short period of use without turning off for cooling, etc.
• Gasoline mini-power plants differ from competitors in their lower cost and the availability of compact models, which makes them the best option when equipping small enterprises, private homes and other facilities that do not require long-term continuous operation of the generator. The disadvantage of this type is low efficiency, low power and low wear resistance compared to diesel solutions.

Generator models

The following generator models are very popular for dachas and private homes:

1. Kipor 5kva

   . Gas single-phase asynchronous generator, rated power 4.5 kW. Equipped with auto start, self-monitoring system and voltage stabilizer. Price 111 thousand rubles.

2. KraftDele KWD-6500

   . German three-phase diesel generator with a rated power of 6.5 (maximum 7.5 kW) and a service life of 100 thousand hours. Equipped with a self-monitoring system, voltage stabilizer and autostart. Price 85 thousand rubles.
3. FORTE FGD6500EW . German welding diesel generator producing voltages of 12, 380 and 230 V. Rated power 6.5 kW, maximum 7.5 kW. Equipped with a stabilizer, auto start, and a self-control system. Price 81 thousand rubles.

4. Honda EG 5500CXS

   . Gasoline single-phase generator, power 5.5 kW. Equipped with the AVR function, costs 124 thousand rubles.

5. WERK WPG6500

   Read also:  Communities › DIY › Blog › Do-it-yourself puller-mandrel for replacing VAZ-2107 silent blocks
   . Chinese single-phase gasoline generator, power 5.5 kW (max. 6.5 kW). Produces alternating current of direct conversion; it is not equipped with automation. Price 74 thousand rubles.
6. Lifan LF5GF-4ES BF . Chinese single-phase gasoline and gas electric generator, rated power 5 kW. Equipped with AVR, auto start, and a built-in digital panel provides parameters about the output voltage, load current, frequency of the generated current, total load power and engine hours from the moment of the first start. Price 75 thousand rubles.

7. Dalgakiran DJ 4000 DG-EC

   . Diesel Turkish mini alternating current generator of synchronous type with autostart, short circuit and overload protection, rated power 3.3 kW. The single-cylinder engine of the device is equipped with an air cooling system. Price 91 thousand rubles.

We invite you to look at a review of this generator.

[su_youtube url=”https://www.youtube.com/embed/XFqDdRqs-Ro?feature=oembed”]

Consumption calculation

The performance of a mini-power plant is a decisive factor when choosing it. If there is insufficient power, the device will be useless, and if there is excess power, resource consumption will be unreasonably high, creating unnecessary and unreasonable expenses.

To determine the optimal parameters, it is necessary to summarize the consumer powers of all connected equipment and systems. 15–30% must be added to the resulting figure. This reserve is necessary to ensure optimal operation of the backup generator at maximum load in accordance with the initial calculations. Most units achieve optimal wear and performance in the range of 40–80% of maximum load. The exception is industrial models that can be operated in extreme conditions for a long time.

Diesel generators: efficiency and reliability

The main advantage of diesel generators is that they have such low fuel consumption that gasoline models simply cannot offer. For continuous operation, only diesel generators are used. Such models are more expensive, but their operation is cheaper (thanks to the low price of fuel and economical consumption). If necessary, multiple diesel generators can be configured in parallel to operate together.

The compression ratio of the fuel directly affects the engine efficiency (the higher the better). For diesel fuel this figure is low. Since it is limited only by the thermal stability of the fuel and the strength of the crank and piston systems, for the efficient operation of a diesel engine, an additional margin of safety (and therefore weight) is built into the design. At high speeds, the device will not last as long as lightweight parts of a gasoline engine. However, this does not make it less durable, but only explains why the diesel generator prefers lower speeds.

Diesel stations are:

1. Mobile. Designed to operate for a short time, therefore they serve as a reserve; it is not recommended to use them as a permanent source of power supply. These characteristics are due to the presence of a high-speed engine (3000 rpm), cooled by air. Such an engine is noisier than the engine of a stationary generator, fuel consumption is high, and the service life is short (about 500 operating hours per year).
2. Stationary. If electricity is required around the clock, the best choice is a stationary diesel generator. It runs on a low-speed engine (1500 rpm) with liquid cooling. A stationary diesel generator is durable, not so noisy, and uses fuel economically. Resource - from 15,000 to 40,000 engine hours per year. The main disadvantages are the significant weight of the generator in comparison with the mobile model, as well as the high price.

The noise level of a diesel generator ranges from 80-110 dB. The permissible minimum load (kW) for continuous operation is 40%.

Engine cooling type

1. Air cooling is used on low-power standby generators. For effective heat transfer, they require well-ventilated rooms or individual ventilation. The presence of such a system has a positive effect on the cost of operating a mini-power plant. The disadvantages of this group include minimal efficiency with high resource consumption and additional noise.
2. Liquid cooling is used in power plants that can provide electricity to large production facilities and enterprises. The advantage of backup generators in this category is minimal noise and maximum efficiency even during long-term operation with critical loads. Disadvantages include additional costs for heat exchange fluid and higher cost.

Gasoline generators: design and application

A carburetor (gasoline) engine is convenient if you need a low or medium power station (up to 9 kVA). Gasoline generators are indispensable if the priority is the lowest possible noise level, light weight and compact size of the station. Gasoline generators are quite simple to use. They are used as an emergency power source or for power supply during expeditions, on construction sites, etc. Gasoline generators are cheaper than diesel ones, but high fuel costs “eat up” all the savings over time. The main disadvantage of air-cooled gasoline models is the inability to use them as a constant source of electricity; only liquid-cooled diesel generators are suitable for this.

The low power generator up to 2 kVA is equipped with a two-stroke engine with one cylinder. It is not designed for long-term operation (maximum 500 hours). Generators with average power ratings (from 3 to 9 kVA) are manufactured on the basis of a 4-stroke engine with one or two cylinders. The optimal configuration of such a motor is with overhead valves (OHV), which ensures increased engine life, stable and quiet operation. Models with power from 9 to 15 kVA have V-twin engines with two cylinders, providing an even longer service life (2500-4000 hours).

A low-power household carburetor generator may have a manual starting method (using a cord). A combination of cord and electric starter is possible. Auto start is a feature that is usually found in high power models (both petrol and diesel).

The noise level of a gasoline generator is less than that of a diesel generator (55-72 dB). The permissible minimum load (kW) for continuous operation is 10%.

Noise insulation

In most cases, noise protection is not needed for mini-power plants installed in dedicated premises and remote areas. According to industrial safety standards for mechanisms operating within the city, the noise level must be below 80 dB. For rooms or areas with special requirements, installations equipped with silencers and/or equipped with special noise-proof enclosures are used. At the same time, additional accessories increase the price of a backup generator.

Maintenance of diesel generator set

Timely, complete and consistent maintenance is the key to a significant increase in the service life of an electrical installation. The maintenance schedule is drawn up by the device manufacturer and depends on the type of generator.

Maintenance can be scheduled or daily.

Daily procedures

Daily maintenance involves a scheduled external inspection, tracking errors in diagnostic programs, and checking the level of working fluids. Also during the inspection, the condition of fasteners and connections is checked.

Planned maintenance of installations

Factory regulations establish the following maintenance intervals for power plants of this type (with the exception of backup power supplies). The technical serviceability of diesel units is checked at the following marks: 50, 250, 500 and 1000 engine hours, respectively. Maintenance carried out at around 50 hours is called test.

A master performs scheduled maintenance of a diesel generator

Operations performed at the 50 hour mark:

• checking the amount of oil in the crankcase (topping up if necessary);
• checking the current state of the battery;
• draining water from the sump;
• checking fasteners;
• external inspection of pipes, hoses and other lines of the cooling system;
• checking the integrity and tension of drive belts;
• assessment of the level of contamination of the fuel filter;
• replenishing the coolant level.

During routine diagnostics of the diesel generator, a diagnostic card is filled out and stored in the document log.

Regardless of the interval at which the maintenance is performed, upon completion it is necessary to start the diesel generator set at idle speed and warm it up; then it is necessary to evaluate the quality of the power plant at idle. For some models of power generating installations, the regulations provide for replacing the oil filter after test maintenance.

At the 250 hour mark, the same manipulations are performed as at the 50 hour mark. Additionally, change the oil and oil filter at this mark. This operation begins from this mark and is carried out at each subsequent maintenance.

During maintenance-2 (mark 500 mt), replacement of the fuel filter is added to all of the above operations. After another 500 operating hours, the air filter needs to be changed. TO-4 (2000 hours) burdens the owner with replacing the refrigerant and cooling system filters.

When carrying out maintenance, the input cable and connecting wires are checked

This maintenance plan does not apply to emergency or standby power supplies. To maintain their service life, it is enough to carry out maintenance once a year similar to the maintenance of generators of permanent use at around 2000 operating hours. In addition, for such devices a quarterly inspection is carried out with manipulations performed during TO-50.

To extend the service life of a diesel generator in cold latitudes, regulations require seasonal maintenance (usually 2-3 times a year).

Asynchronous or synchronous unit

1. Asynchronous mini-power plants maintain voltage with precise characteristics and without fluctuations, which makes them the optimal solution for powering devices with increased sensitivity to current quality. They have better protection from moisture and dust and are durable. The recommended area of ​​their application: medical institutions, telecommunications complexes and server rooms, as well as power supply for other devices. Standby generators in this group are sensitive to peak loads and cannot be used to service equipment with high starting currents.
2. Synchronous mini-power plants are characterized by lower current quality and increased resistance to short-term overloads. These generators are more efficient when powering devices with reactive loads. They are usually used to service individual housing, food sites, offices and construction sites, where protection from moisture, dust and other aggressive factors can be provided.

Load testing of diesel generator sets

To assess the current service life of the installation, tests are carried out that involve an increased load on the device. During these tests, a number of service actions are performed:

• cleaning the cooling system;
• changing the oil followed by removing condensate;
• replacement of filters and other r/m;
• maintenance of the power plant: adjusting engine valves, rotation speed, checking drive belt tension;
• diagnostics of the control system for compliance with issued commands, checking the installation control panel;
• checking the tightness of the cooling circuit of the diesel generator set;
• calibration of generator stands and supports;
• cleaning power plant compressor components;
• checking the integrity and cleanliness of fuel lines.

After maintenance, the operation of the diesel generator set under load is checked

After completing the tests, the engine will be heavily coked and must be cleaned of accumulated combustion products. After this, a long drying of the main winding of the diesel generator set is required. The test results and repair work carried out after the tests provide a clear picture of the remaining service life of the device, the possibility and feasibility of subsequent major repairs.

Protection class

The level of protection of a mini-power plant determines the conditions under which the operation of this equipment will be safe. This setting is indicated by the symbols IP combined with two numbers. The first parameter indicates the level of protection from solid particles, including dust and mechanical impacts. The second number determines the level of moisture resistance.

It is necessary to select the optimal characteristics of the characteristics for a backup generator taking into account the operating conditions: indoor/open room, shed/street, production site, separate room, and so on.

Generator starting system

The engine starting system determines the efficiency of equipment operation. Mini-power plants can be equipped with an automatic or mechanical system for starting the power unit. The first option involves the use of a special relay, which operates without human intervention, receiving signals from sensors that continuously monitor the parameters of the main power line. It can be equipped with a remote control unit. The automatic start unit is recommended for use when powering systems of high importance, where continuous supply of energy to consumers is required. In other cases, it is sufficient to install a backup generator with a mechanical or manual start.

The information presented will allow you to independently select the optimal technical solution and draw up clear requirements for the manager regarding the required version of the power plant. Our specialists are always ready to help you choose a mini-power plant, as well as provide comprehensive information about the models being sold.

Selecting fuel for the generator

The service life and efficiency of the generator are affected by the quality of the selected fuel and lubricants. Chemical properties and seasonality must be taken into account.

For a gasoline generator, only gasoline without ethyl liquid and having a high octane number is suitable.

For a two-stroke engine with a valve located on the side, choose gasoline with an octane number higher than 77. This is gasoline of the A-80, AI-92, as well as AI-95 and AI-98 brands. A four-stroke engine with overhead valves (OHV) requires grades AI-92, AI-95 and AI-98, that is, gasoline with an octane number above 85.

For diesel stations, the so-called cetane number is important. However, the most appropriate indicators depend on the season. In summer fuel, when work is carried out at high temperatures, the cetane number should be no more than 45. In winter, at temperatures not lower than 35 degrees Celsius, you will need fuel with a cetane number greater than 45. In particularly harsh climatic conditions, arctic fuel is used (it also works at - 50 °C).