Variable frequency drives or variable speed drives can give the much-needed power drop and good operation. Torque and amps generated by an AC motor will outline or delineate the size of variable frequency drive suitable for an application. Make sure that you are buying variable speed drives based on the load stated in the amps, and never solely horsepower. Similar to any control device, picking the ideal variable frequency drive will necessitate great understanding and care, plus appreciating the difference between control with variable speed drives and that with control valves. You cannot get any variable frequency drive and expect that it will offer the ideal results. With numerous options when it comes to variable frequency drives, how do identify the right device or system? We have highlighted in the piece several factors to take into account when purchasing a variable frequency drive and ensure you are buying the ideal device.
First and foremost, make sure you figure out what is the Full Load Amperage (FLA) of the engine you intend to run with your variable frequency drive (VFD). To get the FLA you only need to look at the nameplate of the specific motor you plan to run with your inverter. The information will help you in identifying a drive that suits best your particular motor. If you are choosing your variable frequency drive based only on the horsepower rating, you’re likely to undersize or oversize your inverter. All the VFD firms will list clearly both the horsepower rating and current rating for their inverters in their selection documentation.
Another thing you should factor when it comes to purchasing a variation frequency drive is the application. Make sure you know the type of machine the motor and inverter will be running and find out whether you are using it for either Variable Torque (VT) application or Constant Torque (CT) application. Variable Torque application take account of pieces of machinery that have low-torque needs at slower speeds and high-torque needs during higher speeds. CT application, on the other hand, take into account pieces of machinery that require fixed torque levels notwithstanding speed changes.
Lastly, you should check the interface requirements as you look for a variable frequency drive. In any case, the user will require to present some level of input to make the inverter run, stop, and outline the ideal speed to operate. You may get this input from either an interface with a digital keypad or through inputs from other controls, keys or relays. Make sure you are determining how you wish to interface with you variable frequency drive and decide on one with the most suitable interface choice. Make sure that you are also considering your budget and pick a drive that fits your budget.