What is application of variable speed control?
Variable frequency drives are widely used to control the speed of AC motors, like conveyor systems, blower speeds, pump speeds, machine tool speeds, & other applications that require variable speed with variable torque.
How do I program a variable speed drive?
Take these steps to prepare your system for VFD Programming:
- If there is a jumper wire between +24 volts and LI-1 in the VFD terminals, disconnect one end of the jumper.
- Turn the main control panel switch to “on.”
- Start the control panel to activate contractors.
- Once the VFD is ready you may begin VFD programming.
How do I select a VFD for an application?
The most important consideration when choosing a Variable Frequency Drive (VFD) is to know the type of load that is being applied to the motor because it will determine the size and cost of the VFD. The VFD must have sufficient current capability so that the motor can produce the required torque for the load.
What are variable frequency drives used for?
The most common uses of a VFD are for control of fans, pumps and compressors, and these applications account for 75% of all drives operating globally. Soft starters and across-the-line contactors are other, less sophisticated types of motor controllers.
Where are variable speed drives used?
Variable speed drives (VSDs), also called adjustable speed drives (ASDs), are devices that can vary the speed of a normally fixed speed motor. In HVAC systems, they are used primarily to control fans in variable air volume systems instead of other devices such as inlet vanes and discharge dampers.
Can a VFD increase motor speed?
VFDs can be used to control AC motor speeds by changing the motor’s frequency without sacrificing the output power of the motor. This is done by turning the speed pot (explained in section three) of an AC motor drive.
What are the types of VFD?
The main three types of VFD are VSI, CSI, and PWM.
- VSI type VFDs. VSI stands for Voltage-source inverter. This is the most common type of variable frequency driver.
- CSI type VFDs. CSI stands for current source inverter.
- PWM type VFDs. This is an improved and modified version of VSI type VFDs.
What is a variable torque application?
A variable torque application is one which is usually easy to start and requires more torque as the ac motor speed increased. Examples include Centrifugal Pump, Centrifugal Fan, and Low Viscosity Mixer.
Is it OK to put a disconnect between a VFD drive and the motor?
Resolution: A disconnect can be used between the drive and the motor. This is general practice to assure that power does not reach the motor during maintenance and other non-operating times. Note that the disconnect should not be opened or closed while the VFD is running (outputting voltage from T1,T2,T3).
Is VFD and VSD same?
A variable frequency drive (VFD) refers to AC drives only and a variable speed drive (VSD) refers to either AC Drives or DC Drives. VFDs vary the speed of an AC motor by varying the frequency to the motor. VSDs referring to DC motors vary the speed by varying the voltage to the motor.
Which device can be used to get variable speed?
A variable speed drive is a device used in electromechanical drives to control the speed and torque of an AC motor by adjusting the motor’s input frequency and voltage. Variable speed drives may be either electric, hydraulic, mechanical or even electronic.
Variable frequency drives are widely used to control the speed of AC motors, like conveyor systems, blower speeds, pump speeds, machine tool speeds, & other applications that require variable speed with variable torque.
What is the difference between Damper Control and variable speed drive?
With damper control, the input power reduces as the flow rate decreases. However, under variable speed drive control, the variable torque characteristic of the fan means that the relationship between flow and the speed of the fan is such that the input power reduces in a cube law relationship with the speed reduction.
Why choose variable frequency drives for indoor swimming pools?
Due to decreasing prices of variable frequency drives, VFDs are being used on smaller and smaller systems, such as swimming pool systems. Nearly 40% of the total energy used by indoor swimming pools is consumed by the filtration and circulation pumps which are responsible for maintaining the cleanliness of the pool water.