Rotor type
The type of rotor the pump is equipped with.
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Wet. "Wet refers to rotors that are in direct contact with the pumped liquid. It achieves several advantages. The liquid provides lubrication and cooling of the rotor — which increases reliability, allowing the pump to work for a long time without additional maintenance, and reduces the noise level. The latter is especially important for residential premises, which is why they use wet rotor pumps. In addition, the units themselves are simple (in design and repair), compact and inexpensive. Their main disadvantage is a lower efficiency than in "dry" models — usually up to 50%. It is not critical for domestic use, but wet rotors are poorly suited for high-performance professional models.
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Dry. The name of such a rotor is because it does not come into contact with the pumped liquid. The key advantage of this design over the "wet" one is high efficiency — about 80%. On the other hand, dry rotors produce more noise and are not suitable for residential applications. Therefore, this option is typical mainly for high-performance units designed for industrial use.
Max. particle size
The largest size of solid particles in the pumped liquid, which the pump can pass through without damage and abnormal loads. The smaller this size, the more pure water is required for normal operation. If there is a possibility of larger particles entering the water, it makes sense to attend to the installation of an appropriate filter.
Max. power consumption
The electrical power consumed by the pump during normal operation and maximum performance.
This indicator directly depends on performance — after all, for pumping large volumes of water, an appropriate amount of energy is needed. And the power depends on two main parameters — electricity consumption and the load on the power grid, which determines the connection rules. For example, pumps with a power of more than 5 kW cannot be connected to ordinary household sockets; more detailed rules can be found in special sources.
Shaft material
It is the material from which the motor shaft in the pump is made.
— Cermet. It is a material that combines metals and their alloys with non-metallic components. In modern pumps, different types of cermets can be used, differing in price and quality; usually, the features in each case directly depend on the price category of the unit. However, it is well suited for household models with relatively low performance but is poorly suitable for professional use. Therefore, in pumps of more than 15,000 litres per hour, cermet shafts are rarely used.
— Stainless steel. This material is highly durable and reliable, due to which it is found in almost all categories of pumps — from relatively simple to professional, the performance of which is in the tens of thousands of litres per hour. However, it is somewhat more expensive than cermets.
Country of brand origin
In this case, the country of origin refers to the country from which the product brand originates. A brand, in turn, is a general designation by which the products of a particular company are known in the market. The country of its origin does not always coincide with the actual place of production of the product: to reduce the cost of production, many modern companies transfer it to other countries. It is quite normal for products, for example, of an American or German brand, to be made in Taiwan or Turkey. Contrary to popular belief, this in itself does not lead to a decrease in the quality of the goods — it all depends on how carefully the brand owner controls the production. And many companies, especially large and famous ones, monitor the quality very zealously — after all, their reputation depends on it.
Insulation class
The heat resistance class of the insulating materials used in the construction of the pump. The higher the heat resistance — the more reliable the device, the less likely it is to ignite or break the insulation in case of overload or overheating. In addition, powerful performant units can become very hot even in normal operations.
In modern pumps, mainly the following classes of insulation are found:
— B. Materials with a heating limit of 130 °C. They are the most modest option by the standards of pumps. Use binding and impregnating compositions of organic origin.
— F. For this class, the heating limit is 155 °C — the average for pumps. Such insulation uses mainly synthetic binders.
— H. Insulating materials based on organosilicon binders/impregnators. Due to this, their heat resistance reaches 180 °C.
