Electricity is an essential part of human life today. It is not only useful or necessary, but most of the things humans use in everyday life require the presence of electricity.
The absence or failure of electricity is a real pain if you do not have an electric generator in your possession. You have to admit that the companies that provide electricity are not always able to meet the needs of consumers or users 24/7, and blackout is not good for your electrical devices.
The generator set is a practical device so as not to be deprived of electrical energy.
The autonomy of a generator
The generator set is a process that enables the production of electricity in complete autonomy. It consists of a heat engine which drives an alternator (or generator) which itself supplies alternating current. Depending on the model, the size and weight vary from a few kilos to several tons.
A generator set should normally be self-contained. A starting energy source is therefore needed which can be mechanical, pneumatic or electrical.
The use of a generator
Generators are used either in areas that the electrical distribution network does not serve, or to compensate for a possible loss of electrical power to the latter. In the second case, they are then often used in addition to an uninterruptible power supply consisting of an accumulator battery which supplies an inverter.
These devices are generally used in situations where the interruption of the power supply leads to serious consequences or financial losses, for example in hospitals, industry including the food industry, airports, data centers. , firefighters for interventions, etc.
A generator set is used to power or charge electrical devices in places where there is no electric current.
- A motorhome: a generator specially designed for a motorhome can quickly become essential because the batteries integrated into the vehicle to power various types of electrical devices (television, refrigerator, music, etc.), discharge quickly enough as soon as the vehicle is no longer moving.
- A house: A generator can help you out if you are building your own house on your own and do not have access to a power grid.
- A construction site: if you are on land isolated from any source of electricity, a generator will be essential to power your tools (electric hammers, lighting, a crane, etc. ).
Note: among these different types of generator sets, you can find soundproof, stationary or mobile models.
How to choose a generator?
The generator , an emergency or on-demand power source, is essential for outdoor work, securing an electrical system that cannot withstand any mains failure or even producing electricity at a place not connected to the network.
The generator set is a device that allows to have a power source that they are mobile or that it is fixed in case of emergency and power failure.
The generator set can also be used when needed for specific activities. The lack of a mains connection or the lack of power to the same sector are the two main causes that push the characters and a generator to be able to guarantee the obtaining of electricity in any situation. This often bulky device can run on gasoline or diesel, and be equipped with many comfort options (noise reduction, automatic start, etc.).
Things to consider when choosing a generator
- Space-saving and easy to transport: the lightest generators weigh less than 15 kg. Compact but limited in power, they are carried using a handle incorporated in the hood and can easily be stored in the trunk of a small car. There followed a wide range of more or less imposing models, weighing from a few dozen to several hundred kilos. Some are fully streamlined, others supported by a frame made of mechanically welded steel tubes. The presence of wheels is a factor facilitating movement.
- Noise level: in urban areas or on a campsite, for example, it is preferable to use a "soundproof" gasoline or diesel generator set depending on the power and the desired functions. In this category, the noise measured at 7 m ranges from 55 to about 85 dB (A). Non-soundproofed models can reach 105 dB (A)!
- The starting mode: for occasional use, a manual launcher is sufficient. If the generator set has to be used often, an electric starter is more comfortable.
- The capacitor: basic regulator, it meets common uses at home and on site.
- AVR regulation: this system automatically corrects the voltage in order to maintain a constant speed. Able to withstand overloads on start-up, it is compatible with many devices to be powered. Except those incorporating sensitive electronic components (IT, TV, telephone, etc.).
- Inverter technology: offering optimum current stability, it is suitable for the most sensitive equipment. This is the solution to remember if you are looking for a back-up generator for the home.
Three main types of generator sets
There are several types of generator set and you have a very wide choice when you go to buy one, you can choose according to your needs, according to your use, according to your budget too.
The first distinction is between generator sets according to whether they are fueled by gasoline or diesel. Finally, a third category can be defined with the so-called "soundproof" generators which usually run on gasoline.
The generator set is also ideal for motorhomes, to celebrate an event in the countryside or in a place where there is no electricity supply, but this is not the only reason to buy a generator. . It is also useful for preserving the power failure in your home, which can happen from time to time.
In addition, by having a generator set at home, you can also work without interruption with professional equipment, such as a drill driver, concrete breaker, and even a professional welder can use a generator powerful enough to do its welding work.
The gasoline generator
Generator sets generally consist of a heat engine operating an alternator. Their size and weight vary according to their power which is expressed in Watt (W) or in kVA (active power), as well as in Amperes (A = reactive power).
Gasoline generator sets are suitable for a wide variety of uses. They can be selected as a backup on a construction site or as safety equipment to provide current in the event of a network cut.
The power offered by the classic gasoline generator varies from 1,500 to 6,000 W, which makes it a solution corresponding to very many scenarios.
If you are looking for a generator for home use to support you in your various jobs, this is a gasoline generator that you should give preference to. They deliver a single-phase power supply with a two or four-stroke heat engine.
The diesel generator set
With diesel, a generator set can be used intensively and for long periods. But, as opposed to a gasoline generator, the diesel model produces more noise. Therefore, its use should be reserved for construction sites or areas in which noise pollution can be tolerated.
Do not buy a diesel generator set for home use. The noise pollution is far too important.
Unlike the gasoline generator, which is started mostly manually, starters are found on diesel models. Another advantage of diesel: the power delivered can be single-phase, three-phase or mixed. In all cases, the thermal engine on board this generator is four-stroke.
Note that generators with power exceeding 5,000 to 6,000 W are generally always diesel generators.
The soundproof generator
The noise level will depend on the environment in which the unit will be used (construction site, subdivision or itinerant trade, etc.). It is measured in dB (a), acoustic decibels. For example, an itinerant trade will have to equip itself with a soundproof unit for its working comfort and that of its customers. The sound level can vary from 70 to over 100 dB (a) depending on the model.
The soundproof generator set is smaller and quieter than the other groups just mentioned. The idea is to have less power than on conventional models in order to limit noise pollution.
This is why the power range oscillates most of the time between 600 and 2500 W (it is very rare to see soundproof generators exceeding 3000 W). To limit the noise generated during use, it is a gasoline engine that is found on soundproofed generators.
Unlike conventional generators which are composed of a chassis that is sometimes simple and devoid of external protection, a soundproof generator set adopts a casing which limits the sound generated.
With a two-stroke or four-stroke engine, this type of generator is ideal for occasional use, and in particular in the particular setting for camping or supplying modest equipment (on a market or a fun fair for example).
Categories of people likely to use a generator
There are different categories of people who can use generators. Depending on whether they are specific or professional needs. On the professional level, the uses are also diverse according to the needs and the circumstances.
For example, a hospital should have a backup generator to replace the main source. It must be of significant power in view of the energy consumption observed in this type of environment.
For some manufacturers, the choice may be towards an emergency generator or an EJP type generator. This makes it possible to cut off consumption during off-peak periods.
For occasional use in a place without electricity
If you want to buy an electric generator to have light or to be able to use some electric tools in a somewhat isolated place without electricity, a 4-stroke gasoline generator with power around 4000 W and manual start will be there. ideal for you, and capacitor regulation will suffice.
For quiet, short-term use
When you want to get electricity during your countryside vacation or you want to go on an adventure with your friends or family in tents, or a vacation in a motorhome. The portable and soundproof generator set will be perfect for you, it will allow you to charge your phones, tablets, lap top, different electronic devices, and you can even watch TV, boil water with the kettle, or use your coffee maker if you want.
For professional use
If you are a professional who will carry out work in sites without electricity or if you are the owner, the ideal generator set for you is a group with a slightly higher power, of 10 kW minimum, and it must be diesel, and it does not matter if it is towable or not, and as for the power supply, single phase or three phase, it is necessary that the device is able to deliver both. And in terms of regulation, it is recommended to opt for AVR (Automatic Voltage Regulator) regulation to have constant current stability.
For home use
When the reason for your purchase of a generator set is to predict the power outage or you want to install a back-up electric generator for your property, it is advisable to opt for the 4-stroke gasoline model, equipped with a power suitable, about 5000 W, and having an Inverter regulation system, so that your electronic and computer devices are intact. And to ensure more safety, the model with thermal safety and differential cut-out would be the best option for you.
The operation of a generator
A generator set is first of all a heat engine. They run on all fuels. The most common are petrol, diesel, natural gas, LPG, biofuels and, for the most powerful, heavy fuel oil.
This motor is then driven at a fixed speed by means of a dynamo (direct current) or an alternator (alternating current). The whole feeds a generator - which is characterized by the electrical power it can deliver - and which provides electricity on demand. The power supplied by the electric current of the generator set can be single-phase (1 phase + 1 neutral) or three-phase (3 phases).
The power of the heat engine has a direct influence on the electrical power generated. In fact, the more powerful the engine, the more it can drive a large generator.
The unit can be put into operation in different ways: manually, electrically or with compressed air, depending on the power.
Before operating the generator set, a few checks should be made, in particular with regard to the level of oil, fuel, air filter and coolant. Make sure the circuit breaker is open and fuel is flowing. Start the engine. Check that all connections have been made correctly and that the circuit breaker is working.
Manual / Electric start of a generator
In manual mode, the start-up is done using a launcher (identical to that of a mower), in electric mode the device starts when the key is activated as in a car thanks to a small drums.
If you do not use the unit regularly, it is advisable to turn it on from time to time to recharge the battery. However, as a precaution, all electric start generators are fitted with a starter.
On diesel generators, electric mode has the advantage of optionally being able to benefit from an automatic remote start connection in the event of a power cut.
The portable / wheeled generator set
The lightest models (up to 35 kg) are easily transported. For the most part they are equipped with a handle. For heavier models, casters with brakes or a wheelbarrow kit (i.e. two large wheels at the front and two handles at the rear are standard or optional equipment depending on the manufacturer.
For very large models, a hook is provided for lifting with a crane, they can also be installed on a trailer.
Engine speed of a generator set
For so-called "inverter" units, the motor speed will adapt to the current demand of the device connected to it, so it is variable from 1500 to 3600 rpm. The diesel and gasoline groups run at 3600 rpm, they have single-cylinder engines with air cooling. They can operate for a few hours (3 to 4 maximum) followed by a rest period of about 30 minutes for cooling
Devices called an electricity generator run at 1500 rpm. These are only diesels with two or three cylinders (see more for large models), with water cooling. These huge machines, which are difficult to transport, are recommended for industries or for completely supplying a home without electricity because they are able to operate much longer.
Two fundamental balances for a generator set
The frequency, for which the engine regulation constantly adjusts the injection so that the power absorbed is equal to the power generated. If we produce too much the frequency increases and vice versa.
The voltage , for which the regulation of the alternator constantly adjusts the excitation so that the reactive power absorbed is equal to the reactive power generated. If too much is produced the voltage rises and vice versa.
A generator set has an advanced production mode
The generator set is used to cover the peak needs of the public electricity network.
In the presence of the normal EDF network, the generator set is in "rest or stand by" mode. It only comes into operation to compensate for peaks in electricity consumption. This is an EJP mode of operation.
The autonomous method of producing electrical energy from a generator
The generator set is used for energy production, supplying a distribution network. This type of installation finds its application on sites where the public distribution network is non-existent, and technically or economically impossible to set up, such as in the mountains, or on an island. The annual running time of these generators is often very long.
The emergency mode of production of a generator
Emergency generators are intended to supply an establishment with electric current in the event of absence or failure of the public network. These generators start automatically as soon as it detects a network failure. This type of generator is installed in buildings where absence from the sector endangers human lives (hospitals or nursing homes) or in the case of loss of productivity (banks or Data centers such as Datacenters).
The efficiency of a generator
The efficiency of generators increases with their power, but remains limited to the maximum allowed by the Carnot cycle, from which mechanical and electrical losses in the alternator and transmission must be subtracted. In particular, moderate power units are characterized by poor efficiency and high consumption.
The regulation of a generator
A modern generator set is equipped with two regulations. The output voltage is stabilized (for example: 230 V) by an electronic device which acts on the alternator. The speed of rotation of the engine and therefore of the alternator must also remain constant in order to guarantee constant frequency and output voltage (50 Hz in Europe).
This regulation is done by a centrifugal device similar to the James Watt ball regulator which directly controls the carburetor or the injection pump. An induction device based on eddy currents such as the one found in older automobile speedometers, or an electronic system can still perform this function.
Generator repair: common breakdowns
The most common generator set failures sometimes occur for no apparent reason when the fuel tank is full. They relate to the engine, the generator, the electricity production system. They sometimes result in malfunction due to poor maintenance. Indeed, certain maintenance operations are mandatory to keep the generator set in perfect condition.
- If your diesel generator set refuses to start, first check whether the valve which supplies the engine with fuel is open, then whether the fuel level is sufficient. This is not the case ? Carefully fill the tank and turn on the tap. Likewise, check the oil level and add more if necessary. Different elements must be switched on for the device to operate: the on / off contact button must be on "on" and the circuit breaker must be on "off".
- If your generator set is still not working, replace the surge fuse, taking all necessary precautions.
- Is your generator set not producing electricity? The fault is surely in the alternator. You should first look at the alternator circuit breaker: its flow may be closed. In this case, set it to “on”. Likewise, check that the differential circuit breaker is open. The problem may be with the surge fuse that is worn out and needs to be replaced, or the device is not earthed, triggering a safety device. A connection is then necessary.
- If the generator set suddenly stops even though it was working perfectly well, the surge fuse is probably the cause. Replacing it will fix the problem. It could also be a simple lack of fuel or oil. Checking the levels and filling the tanks will help the unit to restart.
Last probable cause: the differential circuit breaker has tripped. If no security risk is detected, the device will restart.
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