Even short-term power outages can cause serious inconvenience. If your house is equipped with a modern boiler with an electronic control system, and it happens in winter, the most unpleasant consequences are possible, up to the formation of ice in the batteries and pipes. You can choose more here https://electrogardentools.com/p/best-12000-watt-portable-generator/
To prevent this from happening, it is necessary to buy a generator, which will be a reliable backup power source and will provide power to the summer cottage or tourist camp located far from the power lines. Let’s take a look at the main characteristics to look out for when buying a generator for your home.
The type of fuel consumed is distinguished:
- Gasoline. The best power generators for back-up power at home or summer cottage. Due to their compact size, low noise level, and affordable price, they are popular among owners of private households, summer cottages, small businesses, and shops. If necessary, you can find gasoline units with a capacity of up to 10 kW, which can cover the needs of any household appliances.
Electric generators with a four-stroke engine are the best choice for domestic use. Their advantages are reduced fuel consumption, long service life, long service life, and excellent power output.
- Diesel. Designed for heavy loads and constant use. Their service life is 2-3 times higher than that of gasoline ones, and fuel costs are 15-30% lower. Due to their higher price, they are worth buying for permanent or long-term power supply at home.
- Gas (dual-fuel). Universal units capable of running on gasoline or natural (bottled) gas. Gas is much cheaper than gasoline, but filling cylinders and storing supplies is a challenge. The problem can be solved by connecting the device to the gas main. Gas generators are mainly used for back-up power supply.
The maximum load that can be connected to a generator is determined by its capacity. According to this criterion, aggregates are divided into four categories:
- Low (up to 3 kW). So much is needed for lighting, refrigerator and water pump operation. The cheapest option for emergency power supply.
- Average (3-5 kW). There is enough electricity to additionally turn on a TV, computer or electric stove.
- High (5-10 kW). This is enough for an autonomous life in a cottage with an electric boiler, air conditioning, electric heating and a set of household appliances.
- Professional power plants (over 10 kW). Used in large workshops, workshops and shops. An industrial or business option that does not make sense to buy for household needs.
NUMBER OF PHASES
There are single-phase, three-phase and universal generators on the market:
- single-phase provide consumers who need 220 volts;
- three-phase give 380 volts, which is necessary for professional equipment;
- universal (220/380 volts) have two outputs, to which you can connect any device.
For domestic use, 220 volt models are suitable. The exceptions are cases when a three-phase network is connected to the house and 380 volt equipment is installed. Before buying, consult a manager.
- The manual start is used on emergency generators not connected to the mains. Their engine is started with a cord, like a chainsaw.
- The electric starter is installed on powerful devices, the engine of which is difficult to turn by hand. Such models are more convenient to use, but less reliable, more expensive and require monitoring of the battery condition.
- Automatic start allows instantaneous power backup in case of voltage drop. The complex management system greatly increases the price. Therefore, they are not very popular for home use.
- Air cooling reduces the cost of the generator, but limits maximum power output and continuous operation.
- Water cooling is used on high-power diesel generators that can power your home non-stop.
- Asynchronous or brushless – short circuit proof, cheap and reliable. They have no brushes or rotor windings. However, its unstable voltage is not suitable for powering sensitive electronics.
- Synchronous ones are more expensive, heavier and require regular replacement of brushes. But they provide high-quality current required by sensitive electronics.
The inverter units are equipped with an electronic board that constantly monitors the output voltage and load current. Thanks to the feedback, they give out a sine wave without drops and jumps. Such devices do not contain heavy transformers, which increase their price and weight.
HOW TO CALCULATE GENERATOR POWER
The instructions for each model indicate the maximum current. To find out the power of an electric generator, you need to multiply the output voltage by the current. If the voltage of the device is 220 V and the current is 15 A, then the power is 3.1 kW.
CALCULATION OF THE TOTAL POWER OF ELECTRICAL APPLIANCES
To calculate the total energy consumption, it is necessary to add up the rating indicators of the power of electrical appliances that need to be supplied with electricity.
Devices with reactive load, which directly convert electricity into thermal energy, consume as much as it is written in the passport. A vacuum cleaner, microwave oven and a pump with an electric motor create an additional reactive load. To calculate it, cos f is used, which is indicated in the instructions. So, a vacuum cleaner with a power of 1 kW with cos f = 0.8 will require 1.25 kW.
The generator has its own cos f value, which must be taken into account when calculating the maximum reactive load. You need to divide the reactive power by this number to find out how many kilowatts of energy an electrical appliance will need. If the cos f of the generator is 0.8, then the total consumption of the said vacuum cleaner will be 1.25 kW / 0.8 = 1.56 kW.
STARTING CURRENT RATIO
To start a washing machine, air conditioner and other equipment, a resource is required that is higher than for work. For most household electrical appliances, this figure ranges from 1 to 3. It can be seen in the instructions supplied by the manufacturer. This must be taken into account when calculating the generator power.
For normal operation of the installation, it must be underloaded by at least 20%.
The formula for calculating the power of an electric generator looks like the sum of the power of energy consumers (taking into account the cos f of the consumer and the generator), multiplied by 0.8.
When connecting 10 bulbs of 60 watts each and a 1 kW pump with cos f = 0.8, the required generator power with cos f = 0.85 will be equal to:
10 * 60 + 1000 / 0.8 / 0.85 = 600 + 1470 = 2070 watts.
HOW TO CHOOSE AN ELECTRIC GENERATOR
A 220 volt air-cooled gasoline generator is suitable for back-up power at home. The minimum capacity of the unit must cover the needs of the lighting and the water pump. For a comfortable stay, it is worth buying a model capable of supplying energy to lamps and a pump, an air conditioner, an electric stove and a computer. The volume of the fuel tank does not really matter.
If you need a constant source of electricity, take a look at water cooled diesel generators. It makes sense to use gas devices only if there is a gas main.
Additional options (display, hour meter, engine heating) are convenient. But it is worth overpaying for them only when the generator is constantly running. Taking an expensive model with many additional features to run it several times a year is pointless.
If you are at a loss as to which generator to choose for your home, start from the purpose of the purchase: the main or backup source of electricity, and the type of premises (permanent or seasonal).