How to choose a power generator?

How to choose a power generator?

Do you know how to choose the right aggregate? Are its size and power important? What functions to pay attention to? Here is some useful information that will help you choose the right model.

In the beginning, you should consider what the unit to buy properly will serve, and what electrical equipment will be used. Below are the two main divisions of electrical receivers.

  1. Electrical devices are divided into single-phase 1 ~ 230 V and three-phase 3 ~ 400 V. The first ones are devices with low power (RTV equipment, electronic equipment, power tools, single-phase motors). The second group are high-power devices (induction cookers, powerful three-phase engines, advanced heating systems).
  2. Electrical devices are also divided into variable power characteristics. There are resistive receivers (household appliances, electronics, lighting), inductive receivers (single and three-phase motors, power tools) and nonlinear receivers (computer equipment, UPS).

On the occasion of non-linear devices, it is worth mentioning the automatic voltage stabilisation function (AVR). It is particularly useful when it comes to supplying tools sensitive to voltage changes, such for example, the computer mentioned above hardware.

Another critical step is to choose the aggregate in terms of its performance. Estimation of the total power of the attached devices will allow you to select the optimal aggregate and avoid unpleasant situations. If at the moment of turning on the power, a fuse immediately popped out, although the estimated power of the devices was properly calculated, we will answer below, why?

Each electric receiver has a nameplate, from which all parameters relevant to us can be read. The power of the device is always given in the active unit, i.e. in kilowatts - kW.
It should be remembered that the electric receiver consumes much more power during the start-up. To avoid any problems with the power supply, it is necessary to check precisely what starting individual devices need current. For example, an electric grinder requires approx — 30-40 % more power than the value given on the nameplate. In the case of electric pumps or motors, this value can be up to 900%!

That is why it is worth to do a detailed analysis of the power demand and add the appropriate reserve.

If we already know all the parameters, it is worth paying attention to the construction of the aggregate. You can choose from aggregates on a standard frame or with soundproofing, which we can use for commercial applications, where noise levels are at stake.

Good to remember

Three-phase aggregates are very versatile devices, also equipped with single-phase sockets. It should be added that the single-phase power of the source of the generator set should be 1.2 times higher than the sum of the power of all simultaneously connected devices. We can not take more than 60% of the power given in its specification from the single-phase sockets of a three-phase generator. For example, a three-phase aggregate with a capacity of 10 kVA for single-phase sockets can transmit power not greater than 6 kW. For three-phase sockets we naturally connect three-phase devices, always providing adequate power reserve for start-up and correct operation of electrical consumers.

Did you know, that?

In low-power, three-phase power generators, a simultaneous supply of devices from single-phase and three-phase sockets, the phenomenon of asymmetry of loads may occur. This is particularly dangerous because it can lead to damage to the electrical consumers and even generator generators.

If the aggregate power is given in kilovolt-amps (kVA), it should be converted into kilowatts, using a simple formula: P = S * cos φ. P - the active power of the receivers (kW), S - apparent power for the receivers (kVA), cos φ in the case of three-phase aggregates is usually equal to 0.8. For example, if we chose an aggregate with a capacity of 10 kVA after making calculations, the active power is P = 10 * 0.8 = 8 kW. This is the maximum power that we can charge our aggregate.

What is the ats system?

The ATS (Automatic Transfer Switch) system is the system responsible for the automatic activation of the emergency power supply. The system monitors any power outage and immediately responds by starting the aggregate. This system is particularly useful in places exposed to power outages, such as offices, workshops, cold stores or production plants.

We choose the Unit to be used in the household

The aggregate will be used to power a 1 kW computer, a 0.8 kW TV, a 2.2 kW vacuum cleaner and a 3 kW single phase electric motor? How much total power must an aggregate provide us with?

  • Computer 1 kW * 1,2 = 1,2 kW,
  • Television 0.8 kW * 1.2 = 0.96 kW
  • Vacuum cleaner 2,2 kW * 1,2 = 2,64 kW
  • Single-phase electric motor 3 kW * 3 = 9 kW.

The power capacity of our devices is 13.8 kW, which is equivalent to 17.25 kVA per kilovoltage meter. All machines are single-phase, so we only need a single-phase aggregate with power above 17.25 kVA. The aggregate should be equipped with the AVR function.

Nevertheless, regardless of your own experience and calculations, it is always worth asking our specialists from for professional advice when choosing the purchased equipment. This will save time and select the most optimal material.

Press Yes if you agree to processing your personal data (after 25th May, 2018) while using It includes using cookies and automatic profiling. As a result we are going to analyze your personal as well as statistical data. The above mentioned data will be used in marketing as well profiling while using Administrator's services. The consent is voluntary. What is more you can withdraw your agreement at any time by sending an email You will find Privacy Policy - Cookies HERE: PRIVACY POLICY - COOKIESYes