Comparison Sigma 5710721 vs Sigma 5710831

The rated power of the generator is the highest power supply that the unit is capable of delivering without problems for an unlimited time. In the “weakest” models this figure is less than 1 kW, in the most powerful – 50 – 100 kW or even more ; and generators with welding capabilities (see below) typically have power ratings ranging from 1 – 2 kW to 8 – 10 kW.

The main rule of choice in this case is this: the rated power must not be lower than the total power consumption of the entire connected load. Otherwise, the generator simply will not be able to produce a sufficient amount of energy, or it will work with overloads. However, to determine the minimum required generator power, it is not enough to simply add up the number of watts indicated in the characteristics of each connected device - the calculation method is somewhat more complicated. Firstly, you need to take into account that only the active power of various equipment is usually indicated in watts; In addition, many AC electrical appliances consume reactive power (the "waste" power consumed by coils and capacitors when operating at that power). And the actual load on the generator depends precisely on the total power (active plus reactive), indicated in volt-amperes. There are special coefficients and formulas for its calcula...tion.

The second nuance is related to the power supply of devices in which the starting power (and, accordingly, the power consumption at the moment of switching on) is significantly higher than the rated one - these are mainly devices with electric motors such as vacuum cleaners, refrigerators, air conditioners, power tools, etc. You can determine the starting power by multiplying the standard power by the so-called starting coefficient. For one type of equipment it is more or less the same - for example, 1.2 - 1.3 for most power tools, 2 for a microwave, 3.5 for an air conditioner, etc.; More detailed data is available in special sources. Starting characteristics of the load are necessary, first of all, to assess the required maximum power of the generator (see below) - however, this power is not always given in the characteristics; often the manufacturer indicates only the rated power of the unit. In such cases, when calculating for equipment with a starting coefficient of more than 1, it is worth using the starting power, and not the rated power.

Also note that if there are several outlets, the specific division of the total power among them may be different. This point should be clarified separately - in particular, for specific types of sockets (for more details, see “230 V sockets”, “400 V sockets”).

The maximum power supply that the generator can provide.

This power is slightly higher than the rated power (see above), but the maximum performance mode can only be maintained for a very short time - otherwise overload occurs. Therefore, the practical meaning of this characteristic is mainly to describe the efficiency of the generator when operating with increased starting currents.

Let us remind you that some types of electrical appliances at the moment of startup consume many times more power (and, accordingly, power) than in normal mode; this is typical mainly for devices with electric motors, such as power tools, refrigerators, etc. However, increased power for such equipment is needed only for a short time; normal operation is restored in just a few seconds. And you can evaluate the starting characteristics by multiplying the rated power by the so-called starting coefficient. For one type of equipment it is more or less the same (1.2 - 1.3 for most power tools, 2 for a microwave, 3.5 for an air conditioner, etc.); More detailed data is available in special sources.

Ideally, the maximum power of the generator should be no lower than the total peak power of the connected load - that is, the starting power of equipment with a starting factor above 1 plus the rated power of all other equipment. This will minimize the likelihood of overloads.

The working volume of the engine in a gasoline or diesel generator (see "Fuel"). Theoretically, more volume usually means more power, but in fact, everything is not so clear. Firstly, the specific power strongly depends on the type of fuel, and in gasoline units, also on the type of internal combustion engine (see above). Secondly, similar engines of the same power can have different volumes, and there is a practical point here: with the same power, a larger engine consumes more fuel, but by itself it can cost less.

The operating power of the engine installed in the generator. Traditionally stated in horsepower; 1 HP approximately equal to 735 watts.

First of all, the rated power of the generator directly depends on this indicator (see above): in principle, it cannot be higher than the engine power, moreover, part of the engine power is spent on heat, friction and other losses. And the smaller the difference between these capacities, the higher the efficiency of the generator and the more economical it is. However high efficiency affects the cost, but this difference can pay off with regular use due to fuel savings.

The volume of the fuel tank installed in the generator.

Knowing the fuel consumption (see above) and the capacity of the tank, you can calculate the operating time on one gas station (if it is not indicated in the specifications). However, a more capacious tank is also more bulky. Therefore, manufacturers choose tanks based on the general level and "voracity" of the generator — in order to provide an acceptable operating time without a significant increase in size and weight. So in general, this parameter is more of a reference than practically significant.

As for the numbers, in low-power models, tanks are installed for 5 – 10 liters, or even less ; in heavy professional equipment, this figure can exceed 50 liters.

The total weight of the unit - as a rule, excluding fuel; The full fill weight can be easily determined by knowing the tank capacity.

In general, more powerful generators inevitably turn out to be heavier, but models with similar characteristics can differ noticeably in weight. When assessing these differences and generally choosing an option based on weight, it is worth taking into account the specific application of the generator. So, if the device will often be moved from place to place - for example, when used “on the road” - it may be worth paying attention to lighter units that are more convenient to transport. However, it is worth considering that the downside of a lightweight design is often an increased cost or a reduced degree of protection. But for stationary use, you can not pay much attention to this parameter - or even the opposite: choose a heavier (and, as a rule, more advanced and functional) option.

Regarding specific numbers, it is worth noting that modern generators in general are quite massive. So, a small weight for such equipment is considered not only up to 20 kg, but even 20 – 30 kg ; Many units weigh 150–200 kg, or even more, and the weight of stationary industrial models is already measured in tons.