I believe that many customers often find that when purchasing pumps, the pumps selected by different manufacturers sometimes have different motor powers. In response to this case, today we will talk about how to correctly select the matching motor power of the pump.
Some clients are wondering why the motor power selected by different manufacturer sometimesis different. Some matching motors have high power, does it means that the pump is inefficient? Conversely, if the power of the matching motor is small, does it means that theefficiency must be high?
For these problems, first of all, we must find out what factors affect the power of the matching motor of the pump before we can make a judgment.
The factors that affect the power of the matching motor are: flow rate, head, medium density, medium viscosity, medium temperature and pump efficiency.
After the customer has finalized the number of flow rate, head, medium density, medium viscosity, and medium temperature, also the pump efficiency assumed to be the same, then the matching motor power should be the same no matter who selects it.
At this time, if the power of the matching motor is selected to be small, it is obvious that the motor used in this way will cause the safety factor to be too small. Once the rated point is exceeded, there may be full load, overload or even burn out for the motor.
For a case encountered in actual operation, some manufacturers do not fully understand the customer's conveying medium and application conditions when selecting and quoting, and usually select the matching motor power according to the proportion of water "1". However, the specific gravity of the medium in actual use by the customer is ">1". For example, when 98% concentrated sulfuric acid is transported, the specific gravity is 1.83. If you still select the models based on"1". The power is definitely not enough, so in practical applications, the matched motor will heat up or burn out. Our Tengyu technical engineers will fully consider factors such as the medium conveyed by customers and working conditions when selecting models, so the safety coefficient will be higher.
For another example,for centrifugal pumps, when the dynamic viscosity of the medium is greater than or equal to 20cP, our technical engineer will find out the correction coefficient of efficiency, flow rate and head according to the viscosity conversion chart, and then determine the expected efficiency of the medium according to the correction coefficients. As well as the flow rate and head of the test medium, namely water, when the viscosity is high, the expected efficiency of the corrected medium will be lower than the theoretical hydraulic efficiency.We must consider the influence of this factor on the power of the selected motor to ensure that the motor is not overloaded when the pump is running.
Therefore, before each model selection and quotation, Tengyu technical engineers or sales consultants will repeatedly communicate with customers and confirm the working conditions on site with the purpose of ensuring our pumps could run smoothly.
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