Morgan Byres | Nov 1, 2018
A variable frequency drive (VFD) is a controller that runs and monitors your pump. Its main feature is the ability to control the speed of your pump’s motor. This is done by adjusting the frequency of the current to the motor which allows you to adjust the speed of your pump, giving you more control of the flow and pressure. Using a VFD also has many other benefits, for instance, ramping the acceleration of the pump can extend its life, and from not always running the pump at full speed saves electricity. The VFD also has overload protection that shuts down the pump in case of an over current - protecting your pump and the rest of your system and providing diagnostic information such as amp draw and voltage for troubleshooting.
Picking your VFD
First, ensure that the VFD you have selected is compatible with the input voltage of your building. The common voltages are 115-230 single phase, 208-230 3 phase, and 460-480 three phase. Next, you need to pick the horsepower of your pump. If you think you are going to upgrade your pump in the near future, getting a slightly more powerful VFD won’t hurt.
Know your phase
I will spare you the details of single vs. three-phase power (though if you’re interested there’s a great primer on this topic over at oempanels.com), but selecting a VFD does require some understanding of the electrical service in your shop. Single phase power is the most common household power circuit, while industrial spaces also have three phase power for running equipment with larger power requirements. Some smaller businesses may not have three phase and have to rely on single phase power. Up until recently, you would have to have three phase power in your building in order to run a VFD and to adjust the speed on your pump. However, thanks to modern technology we have a VFD that converts single phase power to three-phase power. This gives even the smallest processors the power of three phase, and the ability to control your pump.
One thing to note is that the motor on your pump MUST be designed for three-phase power if you want to use a VFD, even if you are using one of our converting VFDs.
Are you going to be using this pump in or around a lot of fluids or in highly dusty areas? (If you’re a brewery, winery or distillery then the answer is yes, yes you are) Then you probably will want a VFD with a NEMA 4X standard enclosure, which means it is dust, wind, and water resistant. Are you using this pump around high proof alcohols? If so, you may want to use an explosion-proof VFD and motor to prevent the risk of, you guessed it, explosions.
Why we recommend KBDA Drives
The KBDA drive is our favourite VFD. In somewhere as unpredictable as a brewery, we think it is super important that your VFD is as durable as possible, so these VFDs are built with an aluminum NEMA 4X casing, instead of plastic as many are these days. These KB Drives have a digital readout that displays the speed of your pump and diagnostic information. This is an extremely helpful feature that helps you regulate your process. If you find the perfect speed to run your CIP you can record it and make sure to run the pump at the same speed each time.
When we put together our portable assemblies, we match the horsepower abilities of the VFD to the pump selected. While our assemblies are amazing, they are not the only way to have a VFD. If you buy a VFD separately it is quite straightforward to attach and set up so it is never too late to buy a VFD for your pump! Give us a call and we will help you select the right one.