Statistics are stubborn and undeniable figures, and they show that the worldwide sales of generators are constantly increasing, and sales are not simply growing, but growing exponentially. According to the intermediate results of this year, generators have already become an undisputed sales hit and covered the volume of the last year twice. There is almost six months ahead, and the peak of sales of mini-power plants falls on the autumn-winter period.
The media are busy proclaiming that the increase in sales of generators means that many countries are very scared of power and gas outages. They buy boilers to heat the water, electric heaters – to heat houses. In other words, electricity is needed more than ever, and the supply of coal at thermal power plants seems to be at zero degree, and all nuclear power plants are under repair and preventive maintenance. In general, the situation is really tough. The only way out of the problem is to buy a generator. A diesel one will be fine if you need long-term trouble-free operation.
That’s true. The only thing we do not agree with is that it is fear that leads you, a smart and practical. To buy a generator for backup supply or for a constant supply of electricity is not a fear, but a serious and thoughtful decision of a down-to-earth person. After all, the power outage even for a couple of hours forces the owners to postpone household chores, in houses with an electric stove it is impossible to prepare food, children are forced to prepare school lessons by candlelight or other weak additional lighting. In general, the whole comfort of home is ruined. If electricity is cut in the enterprise, in the working office space, things are even worse. Production stops, all computer operations are interrupted, and it’s all a waste of huge amounts of money and the failure of important transactions.
The question usually arises with the purchase: How to choose the commercial standby generator with enough power and necessary functionality? Choosing a generator is not an easy thing. But this, nevertheless, is easier than learning Chinese language. Anyone who understands why he/she needs the unit can learn a few simple rules when choosing a backup power plant. We have selected the most important ones for you.
LET’S START WITH CALCULATING THE TOTAL POWER OF THE APPLIANCES
If we put aside the brands and various functions, it turns out that the price depends on capacity. The more powerful – the more expensive. However, you should never be guided by the price, it is better to start the choice with the calculation of how much the commercial standby generator must produce to determine your wattage requirements. If you buy the one with less power in order to save money, it may occur that the power is corny not enough. Electrical appliances simply will not turn on, or there will be an overload and it will begin to choke, or even break down. This is one mistake, and the second is the choice of a very powerful generator. In this case, part of the power is not used, the fuel is burned, and a lot of money is let to go down the wind. Therefore, you should first of all calculate the required. To do this you should:
- On a piece of paper list all the electrical appliances in the house with their powers in watt in front of each. The power of each electrical device is indicated on the label or specified in the device passport.
- Divide all electrical appliances into vital and those you could temporarily avoid. The most necessary are lighting, refrigerator, electric stove, in winter – heaters, gas boiler starting block. Water pump, boiler, computer are also very important for comfort in the house. But cleaning with the vacuum cleaner, ironing and laundering using the generator, this verge on luxury.
- Select all electrical engineering which will work constantly and simultaneously. The sum of its capacity is the real power you need. Also select interchangeable electrical appliances, e.g.: you can turn off the computer and watch TV, either to iron or to do the washing not turning on the lighting or electric stove. All this is to be summarized. But that’s just a rough calculation.
- What is the starting current ratio? It is an important thing when choosing a generator is the starting current ratio and often indicated by the manufacturer directly on the device or in the data sheet and is marked as “cos” (“cosine phi”). The essence of “cos” means indicating the required bigger power for device starting up than for its operation. Therefore, the power of each selected unit of electrical equipment must be multiplied by this index. You’ll get a bigger number, but this does not apply to all electrical appliances. If the device only needs current to heat it, then its cos is 1 or slightly more. It is not important when calculating power. Such devices are light bulbs, heaters, irons, boilers, kettles, electric stoves. But if the electrician performs other functions (forces something to turn, move or starts complex circuits), then there may be 2 or 3. In a welding machine, for example, such a factor must be multiplied by the power of the device to get the number of the required starting power. For example, a vacuum cleaner has a starting current ratio of 1.5. If the power of the vacuum cleaner is 2 kW, then to run it needs: 1, 5×2=3kW. If you left 2 kW of power for the vacuum cleaner, it simply will not turn on, because it needs 3 kW to run.
Table of appliances starting currents
|Name||Power rating (wattage requirements)||Starting current ratio||Starting power (watt)|
- Do not forget about the power reserve. For normal operation of the generator, without overloads, you need to have power reserve. To do this, add 20% to the resulting capacity. Such reserve will prevent from breakdowns and will be saving in the case when you buy some new electrical equipment. For stationary power plants it is better to add even 30%, because their work will be uninterrupted.
Calculator for generators power computation
Required power of the generator
|Household appliances||Power (watt)||Amount|
Generator power: kW*
*all calculations are approximate, for more accurate calculations please advice representatives of the specific manufacturer!
MOST POPULAR GENERATOR POWER RATINGS
If you have calculated the required power, but you still doubt something, or the figure turned out to be incomprehensible and off-scale, then carefully read our guidelines for power. We have identified classes for you concerning what kind of power generator is required in a particular case:
- Generators up to 3 kW are household ones. They perfectly cope with the lighting of the cottage or a small house. Power is enough start motor-driven products like a refrigerator, and a small pump for water.
- Generators up to 5 kW – these are also household, but they are worth buying if you want comfort in the house, turned on TV and a computer that is necessary for work or for children. 5 kW of power will give the opportunity to cook on the stove.
- Generators up to 7 kW – the mentioned power is needed to provide electricity to a large house, which has electric heating, a boiler for water, air conditioning, and a water pump. You will be able to turn on various electrical appliances from time to time, such as a vacuum cleaner. Power station will manage not only the house; it is also capable for the establishment, office or medium-sized store.
- Generators from 10 kW; – professional class power plants. They are acquired for businesses, large shops, workshops. In general, for business purposes because there will supply everything, including alarms or freezers in a large supermarket.
Table of popular generator’s capacity
|No.||Capacity||Number of monthly Google requests||Sales statistics|
220, 380 or 220/380 VOLTS GENERATOR
Electric generators are divided into single-phase, three-phase and universal ones.
Single-phase power plants are definitely better to choose for home or summer cottage, because in everyday life we actually do not use three-phase devices.
Three-phase generators have two sockets on the panel: one single-phase 220V/16A and one three-phase 380V/16A, so that they can provide electricity to any current consumers.
Universal stations provide power not only to 1-phase consumers (household appliances, construction tools), but also to 3-phase devices and equipment. Such device is more functional than the previous two ones, it provides maximum comfort for the user, being able to work both on one and on three-phases.
Generator sales statistics by number of phases
However, to take a three-phase generator home standby would be a mistake, because it has its own work specificities:
- How power is distributed. A three-phase power plant gives exactly one third of the total capacity at each phase. It means that, if the rated power is 6 kW, such used generator will not operate a single-phase device with such power. You can only connect a two-kilowatt single-phase electrical appliance. And even three, 2kW each. In addition, in a three-phase generator, an important point is the “load skew”. This means that each phase should not exceed more than 25% of the power in relation to the other phases.
- The most common mistake. It is irrational to buy a three-phase generator for a house with single-phase electrical appliances. It’s wrong to do it even if the electric wiring is laid properly and without a load skew. With the 6kW generator you will power one 1-phase electric appliance of 2 kW, and at the same time it will operate at its full power of 6 kW and consume fuel to the maximum. It is better to buy a single-phase 6 kW one, it will consume much less fuel, and its price is lower.
- Specificities of ATS connection. If there are three-phase current consumers in the house, then reasonable to choose a three-phase power plant, but it is important to know the peculiarities when connecting ATS – automatic transfer switch. The scheme is more complicated in the case when your house is connected to three-phase power supply. At the same time, all current consumers are at a voltage of 220V, and three lines are separated in different parts of your house. There are two possible solutions:
- you can use a three-phase power plant and three-phase automatic equipment. Each power line must be well calculated and laid again taking into account the phase skew, in other words, the difference in the load should not be more than 25%. But this is a complicated process.
- Another option is technically simpler and more affordable. It involves the use of a single-phase power plant and three-phase automation. The ATS continuously monitors each power supply line. If on one of them current is lost, the automation will switch the total load on the generator. If all consumers in the house are single-phase, then all three phases are connected between the automatic transfer switch and the generator, and it supplies all three lines at the same time, simultaneously. This scheme allows you not to conduct the wiring line again and not to worry about the load skew, but it is acceptable only if there are no 380V appliances in the house.
Generator sales statistics by fuel type
Gasoline generators are designed for private homes or cottages. They have proved themselves to be a good reserve when temporary power outages in the network. The advantages of gasoline power plants are: compact size generator, low noise, lightweight and quite an affordable price for mostly all customers. For the house people always buy a gasoline generator with a capacity of 3-5 kW, and for enterprises, shops, offices and retail outlets they choose the ones with power up to 7 kW or even up to 10 kW.
Diesel generators are designed for heavy loads, they are always equipped with a reliable and robust motor, which has a motor resource 2-3 times higher than that of gasoline ones. Their purpose is frequent and long-term usage. In view of this it becomes clear that it makes no sense to buy diesel generators for a house use. However, for places where there are no electrical networks, it is a great idea to choose diesel generators. It has longer time of continuous operation, which reaches up to 10 hours without refueling. Consequently, the device can work more than a shift at a construction site, during repair or installation.
Dual fuel generators are the choice of economical and mindful buyers. Hybrid devices operate on two types of fuel: it can be either gas or gasoline (alternately). A built-in gas module is used to switch from gasoline to gas. The advantage of dual-fuel ones is double savings: on the price of fuel and its quantity. Such a universal generator uses twice less fuel when working on gas, and besides, cylinder gas is cheaper than gasoline. It is very important that the factory gas/gasoline generators are safe to operate, and the current quality remains high on any fuel. The time of uninterrupted operation on one cylinder can be about 20 hours, but in most cases, gasoline units are used as a reserve, not a permanent source of electricity.
What is an inverter generator and is it worth buying
Inverter generators are the most advanced technology, microprocessor inverter board is often called the technology of the future, because the time when it will completely replace common use generators is not far. A huge advantage of the inverter is the issue of pure voltage without drops and jumps, deviations are possible up to 2.5%. Such indicators become real, thanks to the inverter technology: the current converter together with the regulator. The alternating current is converted to a constant, and its characteristics are aligned, and then it becomes alternating again, but with an ideal sine wave at the output. Digital technologies involve so-called feedback circuits and constantly monitor the quality of the current at the output point.
- The inverter device has many advantages over common use ones:
- Low weight
- Compact size
- Fuel saving (more than 40% compared with the ordinary generator)
- Noiseless run
- Little gasoline emissions
- High level protection against dust and moisture due to modern body
Net current is very important for power supply of various electronic devices: computer equipment, medical equipment. Therefore, the inverter is recommended for use in offices, firms, clinics. Choosing an inverter generator for a house is also the right decision, because the sensitive gas boiler start unit switches instantly, if the voltage gives a jump. Also, with the inverter refrigerators and other household appliances work well. For an apartment in a multi-storey building, the inverter is the only way out. It can be installed on the balcony or loggia, making the output of gases through the pipe, and your nearest neighbors will not hear any outside noise. Small size and weight make the inverter ideal for tourism, when picnics, hiking. The cost of the inverter generator is quite high, it is 2-2.5 times more expensive than an ordinary gasoline generator of the same power, but the inverter generator is worth the money, and due to high fuel economy it will recover the expenses very quickly. In addition, having connected the inverter, you may not worry about the integrity and safety of expensive electronic equipment.
Generator start-up, manual start, electrical start, remote start, automatic start
Manual starter is the simplest type of launch. The engine is started by pulling a special cable. This type of launch is simple, but it is suitable only for small and light – household class. To start a more powerful generator, you need to make some physical effort, in addition, at low air temperature, the oil thickens, and it is very difficult or even impossible to pull the start.
Electrical start. In order to avoid the above mentioned problems, high-quality powerful units are equipped with another type of start-up – electric starter. With it, the generator is turned on by turning the key in the electronic ignition lock. This is very simple and easy, and allows you to quickly start a plant in the event of a network outage. The electric starter operates on a built-in 12V battery and does not fail even in cold weather. You can choose a unit with an electric starter, and you can build an electric start unit consisting of a battery and an electric starter into the generator yourself.
Sales statistics by launch type
Remote start. It is very convenient to run the generator from a remote control. Such remote controller has an antenna, it is adjusted to the electric starter. The power plant can be turned on remotely, without approaching it and without leaving home.
Generator with ATS function (automatic transfer switch) is an excellent solution for stores with freezers and refrigerators, as well as for the house. It is connected to the network, and the electronic automation unit gives a signal that there is no electricity in the network, and then the generator starts independently. It is better to choose automatic one, which is triggered to turn on and to shut off when the electric current appears again on the network. These generators save fuel, time and, most importantly – avoid power outages.
BODY: OPEN BODY OR NOISE-PROTECTIVE CASE
The open design implies location of the alternator and motor inside a sturdy metal frame. The frame is made of circular tubes and performs several functions:
- Protection from shocks and damages;
- Fixedness when installation and operation;
- Easy to carry ( or move the generator if there are wheels on the frame)
The advantage of an open-body portable generator is rapid cooling, so open power plants are used for long-term intensive loads, when overheating is possible.
The portable generators of the closed type are designed in the noise-reducing casing, which also serves to protect from damage. The case is good for protection from dust and moisture. To avoid overheating, they installed a reinforced cooling system. This is especially important in commercial diesel generators portable, because they have to endure loads well and work 8-10 hours without a break.
WHICH ALTERNATOR IS BETTER?
Alternator in the generator can be of synchronous or asynchronous type.
- Asynchronous (brushless) is a simpler type, it has no winding on the rotor and no carbon brushes. It is light, cheap, but stable voltage and high-quality current is not his strong suit, so this alternator is not suitable for power sensitive equipment. The brushless generator is necessary for welding operations because it is resistant to short circuits. It is also relevant for construction and installation works, as it has a high degree of protection against dust, dirt and moisture.
- Synchronous (brush) one has a complex structure, it is equipped with copper winding and carbon brushes that need to be changed periodically. The price of the synchronous alternator is higher, it is heavier and dusty premises do harm to it, but it provides better current and stable voltage.
Best winding for the alternator work is copper winding. It has high conductivity ( almost 2 times higher than aluminum) and increased resistance to overheating. Therefore, the life of the alternator with copper winding is much longer. Aluminum winding is used in cheap generators of poor quality. Aluminum is very hot and this negatively affects the output power and current quality.
DO NOT FORGET ABOUT THE VOLTAGE REGULATOR
The presence of the stabilization function is a great advantage. This function is called AVR, it is responsible for the smooth and stable output voltage. The system of automatic voltage regulation is necessary for modern electronics: computer equipment or gas boiler starting block, because voltage surges are harmful for them. You should choose generators with AVR function in case there are sensitive household appliances and electronic equipment.
WHY POWER SOCKET IS REQUIRED ON GENERATOR
On the front panel of the generators there are extension cords for connection. As standard, it is a single-phase 220V/16A (in single-phase one) and two three-phase sockets: one for single-phase devices and one for connecting three-phase equipment. Professional models with a capacity of above 5,000 watts, there is another socket called the power output. It has a current strength of 32 A. The power output makes it possible to remove all the power (5 kW and above) from one outlet, it is extremely important to power up a very powerful electrical equipment.
HOUR METER AND MULTI-FUNCTIONAL DISPLAY
When buying a generator, you should always pay attention to what indicators are reflected on its display. You have to see and control the voltage in volts, the current in amperes, and the frequency in Hertz. High-quality and well-designed generators are equipped with an hour meter. Its indicators are also displayed on the front panel. By controlling the hours worked, you will be able to carry out maintenance of the engine (change the oil, brushes, etc.) in time.
For full and constant control over the parameters of the provided electricity, you should purchase a generator with a multi-functional display. High-quality display works on LED-technology (liquid crystal displays), it always shows the real performance, they are clearly visible even at night.
The engine heating function is powered by a rechargeable battery. The coolant warms up and provides support for a stable temperature of the inoperative engine, which will make it possible to run it without problems. As a rule, the heating system is installed on diesel generators, because the diesel engine is very difficult to start in winter, when the weather is cold. If the generator is located in a closed utility room with a plus temperature, then this lack of heating is not critical, but still important. However, if the diesel generator is running and stored in the open space, we give one hundred percent guarantee that it will be bad and hard to start. Sometimes the launch doesn’t happen at all and as a result you get a useless technique. For such working conditions it is better to choose a generator with a heated engine – the best solution.
BRAND STABILITY AND RELIABILITY
When you choose a generator you should take into account another important thing – it’s a manufacturing company. Customers’ feedback and newsletter signs in the Internet suggest that it is better to buy a generator made by stable and reliable brands. Usually, the companies supplying their generators for decades have a good reputation. They have a lot of service points in all major cities, which mean:
- You know where to go for warranty repairs;
- Repair and maintenance is carried out efficiently and in a short time;
- Required details are always available.
If you fell for the cheap price of the generator and did not pay attention to the brand, you may become a victim of unfair manufacturer, the so-called “one-day company”. Such company will sell their products and disappear from the market, and your warranty card will be no one to present. But it’s not the worst thing, there will come a time when you are ready to pay your own money for repairs, but it turns out that there are no spare parts anywhere, and their arrival is not even expected. Your recently purchased generator becomes a pile of scrap metal. In order not to be trapped, you should choose and buy from trusted brands in reliable outlets. Only better online shops with the auction will always help you with the choice of the generator, they will never leave you with the broken equipment face to face, because such companies are official dealers of the most known and reliable manufacturing companies with a world name.