For example, if your motor is a 20 horsepower motor with a FLA of 56 amps, then you would need to select a VFD with an amp rating of amps, which ends up being around 40 horsepower. Variable speed pumping is a cornerstone of increasing efficiency in pumping applications.
For those users just now implementing this technology, how can you best describe the benefits they will see? The biggest advantage of a VFD is that it matches the amount of work or load on a motor to the amount of energy it needs for that respective load.
This makes the system more efficient and also saves the user money by reducing excess energy from being wasted. When a user implements a VFD in a system benefits are experienced over the life cycle of the pump. Motors associated with pumps tend to be sized where the pump may to meet peak loads, but not necessarily for normal continuous operation or sized for a duty condition where the pump may no longer be required to operate as result of changes in a given system. In such systems VFDs can have a considerable impact in cost savings.
Typically, for every 1 percent reduction in VFD output the user can save 2. Let us assume that we can operate the motor at 85 percent 51 Hz of its maximum speed, it is important to note that any reduction pays that reduction cubed. If you cube 85 percent that result be: 0. This means the true energy consumption would only be In other words, a 15 percent reduction in speed will result in an approximate 39 percent savings in energy costs.
As energy costs continue to rise, it will become more imperative to find ways to cut energy consumption. Variable frequency drives in pumping applications is a key aspect to this effort.
How would you compare the level of control and responsiveness found in a pumping system once a VFD is installed? The large inrush current means that motors will generate a lot of heat, limiting the number of allowable starts before causing permanent damage to a motor.
Learn about the industrial pumps that Hevvy Pumps has to offer your project:. Read the Slurry pump maintenance guide to learn how to maintain your slurry pump for optimal performance.
View slurry pumps USA options. Even working within the limitations of a VFD, there are a lot of situations where the correct VFD and motor selection can provide solutions to tricky problems.
A VFD may not be the solution to every problem, but they can absolutely make the difference between a big problem and a challenging application. If you have such an application, ask your pump pros if a VFD is a solution you should consider! Your email address will not be published. Save my name, email, and website in this browser for the next time I comment.
Frequently asked Question: Should we install a vfd to control our pump? Transistor systems that allow you to turn specific motor poles on and off have been available for decades, but these systems are complex and often lack the fine control needed for industrial pumping. The VFD works by taking in AC power at the 60 Hz frequency, converts it into direct current DC power through a rectifier circuit, and sends it through a DC bus to filter the voltage further.
Then, power reaches the inverter which creates pulses of DC energy that function like AC current. The pulsing nature of the output mimics AC power enough to create the correct induction processes needed to spin the rotor of the motor. Since DC is easier to control in voltage and frequency, using it instead of true AC power allows the VFD to adjust the electrical supply on the fly.
Power is easily increased to a sludge pump under heavy load and then dropped again after a blockage passes or the texture of the slurry or sludge being pumped changes. A pump that is laboring to move a very thick mixture with many solids requires a different amount of power than one that suddenly hits a pocket of thin liquid.
Since a VFD can adjust the operation of the pump on the fly, these sudden changes in operational load are easily compensated for with no interruption in use. Pumping tough, abrasive slurries such as paper pulp or sewage is a challenging process due to high viscosity, the presence of large solids, and changes in viscosity.
All of these issues can damage pumps that are only designed to run at a fixed speed and load. Sludges or other heavy material that need to be pumped when dredging or mining also cause similar issues. VFDs allow slurry pumps and their motors to adjust on the fly to changes in the material being pumped, preventing damage and ensuring the system is always running at maximum energy efficiency.
Gaining variable speed control without costly programmable logic controllers is especially helpful during dewatering processes that require very slow processing speeds.
By utilizing the EDDY Smart Pump Technology , the VFD can be controlled on the fly using on-board smart chips and computers, requiring little to no input from pump operators, thus keeping the pump running optimally with maximum uptime and more profits. Close coupled and single-stage pumps tend to experience less resonance than framed and multistage units. Pumps connected to VFDs have higher grade insulation since operating the pump at a slower than usual speed will interrupt the heat loss pattern.
Variable frequency drives are a type of variable speed drives. The most common type of variable speed drive is Eddy Current. There are two significant differences, however, and this is the short answer: Eddy current drives change the speed of the coupling while leaving the motor speed to run at full speed.
But HOW they do so is the defining difference. VSDs change the speed driven equipment while leaving the motor to operate at its full design speed. In an AC motor, an alternating electric current is passed through distributed stator winding to create a rotating magnetic field that is used to drive a shaft. AC motors drive rotating machines such as fans, pumps and compressors at a single speed and can be found often in heating, ventilation and air conditioning HVAC systems.
The rotational speed and torque of an AC motor is determined by the frequency and voltage of the supply. Since the supply of electricity is constant, then then speed of the motor remains fixed. If speed needs to vary, then a VSD would be effective. When demand for the fan speed decreases, then the fan can be controlled to slow the speed, reduce the energy flow and therefore, reduce energy consumption and overall usage costs.
DC motors convert direct current electrical energy into mechanical energy. DC motors rely on armature voltage and field current to control the motor speed.
A separate DC speed controller is necessary. DC motors are not often chosen for this application. Often, DC motors are retrofitted with an AC motor and AC variable speed drive to accomplish the speed variation needed for its application. Eddy Current drives are VSDs, however, they utilize a DC magnetic field to link two members — one on the input shaft and one on the output shaft.
0コメント