Using a mixer with a Variable Frequency Drive (VFD)
Whether you're buying one from us, or sourcing from another vendor: learn more about VFD usage on industrial mixers.
A variable frequency drive (VFD) is an electronic device that controls the speed and torque of an electric motor by varying the frequency and voltage of its power supply. This allows for precise motor control, energy savings, and improved process performance.
Whether you are sourcing our own VFD or getting one on one of our MXD Process Mixers, here are some things to be aware of.
Proper Drive Sizing
If you are getting your VFD from MXD Process with your mixer, you can rest easy knowing that your drive has been properly sized. If you are looking to get your own VFD, make sure that the VFD is rated for the horsepower and full load amp rating of your motor. You can find your horsepower and full load amps on the nameplate on your motor.
Getting a VFD that is not rated for the motor on your mixer can cause performance issues.
You should also make sure your motor is compatible with your VFD. We use motors that are meant to connect to VFDs, which are 3 phase 230 or 460 volts. Even if you are getting a 120v, 1-phase VFD that will plug into an outlet, your motor will be a 240v, 3-phase motor. VFDs provided by us are only compatible with 3-phase motors unless otherwise specified. If you have a 1-phase motor and you want to add a VFD to it, you should contact us for further information.
If your motor is an explosion proof rated motor, it will not be compatible with a VFD unless it is also inverter duty rated. Do not mount VFDs in explosion areas!
Correct Wiring and Installation
120v, 1-Phase Motors
Now you have the proper drive, sized for your motor, voltage, and amperage. VFDs sometimes require wiring onsite by a licensed professional. All 120v, 1-phase VFDs will arrive with a standard 3-prong plug and will be wired to your mixer unless otherwise specified. These VFDs are ready to be plugged in right away!
230v or 460v, 3-Phase Motors
If your VFD is rated for something other than 120v, 1-phase, it will arrive with what is called “bare wire leads.” This means that the VFD will not have a power cord when it arrives at your location. You will need a licensed professional to provide the cord and outlet that is compatible with your location’s power supply.
Explosion Proof Motors
If you have an explosion-proof mixer, also known as a C1D1 or XP-rated mixer, the VFD will arrive loose and not wired to your mixer. VFDs are not explosion-proof and must be mounted outside of your explosion area. If you purchased an explosion-proof VFD package from us, there will be a NEMA7 enclosure wired to your mixer. This allows you to control your mixer in the explosion area without possible sparking. Mount the VFD outside the explosion area, follow the VFD wiring guide as well as the wiring guide to connect your VFD to the NEMA7 control panel.
Please see our Local Control Package wiring doc for more information. Do not attempt to set up your VFD XP package without a licensed electrician.
In all instances, your VFD will already be wired to your motor unless otherwise specified. If your VFD has been provided separately, you will need to wire the VFD to the motor. Please refer to the VFD installation manual for more information.
Setup
Your MXD Process provided VFD will be programmed to operate your mixer. This is done by setting the appropriate parameters in the VFD. If your parameters are changed it can cause your mixer to operate incorrectly or even damage your mixer. Please consult our Product Support team before making changes to your parameters. You can also contact us if you believe your parameters were changed accidentally or if you need the correct parameter list.
If you are setting up VFD that was not provided by MXD Process to one of our mixers, please refer to the VFD instruction manual for assistance.
MXD Process provided mixers can display the following: shaft RPMs, hertz or amp draw. If your mixer has a gearbox, this has already been considered in the mixer parameters to display your actual shaft RPMs.
Troubleshooting
If your VFD does not operate correctly or does not turn on, please contact MXD Process product support. You may need to verify that your wiring is correct, so it may be helpful to have a licensed professional on-site to verify any wiring.
Final Thoughts
VFDs are safe and reliable ways for many industries to control the speed of their motors. They provide amp overload protection and allow you to fine-tune your mixing process. Contact an account representative to determine if adding a VFD to your mixer order is the right choice for you.