Max. performance
The maximum amount of water that the pump can deliver from the well per unit of time. The choice for this parameter depends on two main points: the maximum total consumption and productivity of the well.
The maximum total consumption is the amount of water that is necessary for the simultaneous normal operation of all points of water intake in the system. Different types of consumers (washbasins, showers, washing machines, etc.) require different amounts of water; exact values can be found in special tables or instructions for specific models of household appliances. And the total consumption can be calculated by adding the indicators of all points of water intake. As for the productivity of the well, this is the maximum amount of water that the well can produce in a certain time without draining it. This indicator is usually indicated in the documents for the well; if it is unknown, before buying a permanent pump, it is imperative to determine the productivity — for example, by trial pumping with an inexpensive unit.
Accordingly, the performance of the pump should not exceed the productivity of the well, and it should be at least 50% of the maximum total consumption of the connected water supply system. The first rule allows you to avoid draining the pump and the troubles associated with it, and compliance with the second guarantees a normal amount of water even with a rather intensive water intake. And, of course, do not forget that
high performance requires high power and affects the cost of the device.
Max. immersion depth
The greatest depth under water at which the pump is capable of operating normally.
The optimal location for the deep well pump is as close to the bottom as possible (no closer than 1 m, but this margin can be ignored in this case). It is worth choosing according to the maximum depth, taking into account the depth of the well and the static water level in it (the distance at which the water mirror is located from the surface of the earth when the pump is turned off). For example, there is a well 50 m deep with a static level of 20 m; thus, the depth to the bottom is 50 – 20 = 30 m, and if you want to lower the pump to the very bottom, the maximum immersion depth must be at least 30 m — otherwise too high water pressure may damage the unit.
pH value
The pH value of the pumped liquid for which the pump is designed. This indicator describes the level of acidity of the medium, roughly speaking, how reactive it is to the “acidic” or “alkaline” side: low pH values correspond to an acidic environment, and high pH values are alkaline. Acid and alkaline have different effects on the materials used in the design of various equipment, including pumps. Therefore, when designing parts in direct contact with water, the pH level must be taken into account, and using the pump with unsuitable water is not recommended — this can lead to corrosion, poor water quality and a quick failure of the unit. At the same time, it is worth noting that drinking water wells typically have a pH of 6.5 to 8, and overlapping this range (and even wider) is not a problem. Therefore, this parameter can be called secondary, and in many models, it is not indicated at all.
Max. liquid T
The highest suction water temperature at which the pump can operate normally. For deep well pumps, the water temperature is also important because the pump is constantly immersed in water during operation, and the liquid provides cooling. Therefore, in modern models, performance indicators are usually low — less than 30-35 °C. However, the temperature in artesian wells, usually, is much lower (the only exceptions are regions with thermal waters, but specific equipment is used there).
Power consumption
The power consumed by the pump motor during operation. A more powerful engine can provide more head and performance, but these parameters are not directly related: two models of similar power can differ markedly in practical characteristics. Therefore, this parameter is secondary, and more or less unambiguously it describes only the class of the unit as a whole — powerful engines are typical for high-end performant models. But what this characteristic directly affects is the actual power consumption; and with it, in turn, are connected not only to electricity bills but also connection requirements.
Power cable length
The length of the standard power cable provided in the design of the pump.
Ideally, the length of this cable should not be less than the maximum immersion depth — this will ensure maximum ease of connection: the connection point of the cable to the mains will be above the water (in the best case, even outside the well), and you will not have to worry about insulation. At the same time, for several reasons, many pumps are equipped with rather short cords — about 1.5-2 m, and not
long cables; in such cases, it is necessary to use special waterproof equipment.
Overload protection
A safety system in case of an overload of a deep well pump when its engine is running beyond its capacity. It can lead to engine failure or even fire. Overloading is usually prevented by thermal current relays introduced into the circuit of pumping equipment.
Country of 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 device: 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", monitor the quality very zealously — after all, their reputation depends on it. However, the range on the market is not so great. In addition to East European pumps, there are models from
Italy and
China.
Impeller material
The material from which the pump impeller is made.
A wide variety of materials are used in modern well pumps. However, the manufacturer, usually, chooses the option so that the strength, reliability, resistance to pollution and other key features of the wheel correspond to the required characteristics of the pump and its level as a whole. In addition, the same material may have several varieties that differ markedly in characteristics; this is especially true for technopolymers and thermoplastics, but most metallic materials such as stainless steel or brass also come in several grades. All this means that when choosing a pump, it makes sense to look first of all at performance characteristics, price category, reviews and other practically significant information, and the material of the impeller is of secondary importance.