When the motor is completely loaded, it will produce 1 HP = (1 X 0.746) kW = 0.746kW. (Input power/efficiency) Equals (Output power/efficiency). Input power = 0.746/0.9 = 0.83kW if efficiency is assumed to be 90%. Actual efficiency will be less than 90% so use the higher number for a safe estimate.
The 0.746 kW load represents a current draw of approximately 940 milliamperes (mA). A typical household circuit breaker should be able to handle this level of current flow without tripping. However, if there are other loads on the circuit outside of the pump, such as lights or heaters, they could possibly cause the breaker to trip.
In conclusion, a 1 HP water pump consumes about 0.83 kW when running at full load. This amount of power is sufficient to run most residential water pumps without overloading them. However, if another device is using the same circuit breakers as the pump, it could cause the breaker to trip.
Calculate the overall power needs as well (energy use rate). The pump efficiency is determined by the pump, as well as the pressure and flow at which the pump is operated, and may be found on the manufacturer's pump chart. The efficiency of the drive motor influences the total power demand or energy consumption rate. Use an efficiency estimate for the motor.
Also consider the load on the pump. If it is not delivering water at a sufficient pressure to meet the household's need, then it is not operating efficiently. Loads that are too high can also cause motors to run inefficiently. For example, if a pump is working hard just to keep up with the water usage of its surrounding area, then it is not operating efficiently.
The efficiency of a pump is relatively low, typically around 20-45%. This means that 80-55% of the energy consumed by the pump is lost in heat. A more efficient pump would save considerable amount of energy. However, there are many other factors that influence the efficiency of a pump, such as type of motor, size of pump, power source used to drive the pump etc. Therefore, it is difficult to improve the efficiency significantly without changing these other factors.
Another factor influencing the efficiency of a pump is the quality of the water being pumped. If the water contains impurities like iron or manganese ions, they will coat the interior of the pump and increase its resistance to movement, thereby reducing its efficiency.
The pump's work is equal to the weight of liquid pushed in time units multiplied by the total head in meters. A pump's input power ("P") is the mechanical power accepted by the shaft or connection in kW or Watts. As a result, the pump's input power is sometimes known as "break horse power" (BHP). Power is the rate of energy transfer per second. Thus, 1 BHP is enough to lift 1 ton in 1 second full-time.
For example, if you were to attach a motor to a pump and connect them together such that when the motor turns clockwise it causes the pump to turn counterclockwise, then the pump will be lifting itself uphill through a hose. Since electricity is turning the motor, power is how much energy is transferred to the pump per second. In this case, 1 horsepower equals 745 watts.
In general usage, the term "horsepower" refers to the output capacity of a single engine or machine tool spindle. The word "horse" comes from the Latin _hors_ meaning "work or action". A horsepower is one twelfth of a kilowatt hour per hour.
So in general usage, a horsepower is defined as the power required to drive a motor at 12 miles per hour for an hour. However, since this definition depends on the speed of the motor, it can be considered a working definition for only one direction of operation.
A typical well pump consumes between 750 and 1,050 watts of electricity. The wattage will be determined by the horsepower of the pump. The pump will typically utilize 1/3 horsepower, or 800 watts, for a typical-sized residence. Starting power necessitates double the watts required for running. For example, if a pump requires 1,500 watts at start up, then 3,000 watts is available over time.
Well pumps are electric motors that rotate a shaft connected to the impeller or blade assembly. The shaft may be direct drive (no gearbox) or driven by a belt or chain. The motor housing contains magnets which interact with a metal impeller housed in a protective casing attached to the end of the shaft. As the motor turns, the impeller pushes water out of the well bore into the surrounding soil area. Water flows back into the tank through a riser pipe when the well has been pumped dry. Pumps can be single stage or multistage, depending on how many times they need to be turned on and off during use. A three-stage pump would require first being rotated by hand to activate the first stage, then again to activate the second stage, and finally yet another turn of the handle to activate the third and final stage. One-and-a-half-, two-, and three-horsepower motors are common for home use.