Variable Speed Systems Sales and Service in Boise & Southern Idaho
A “Variable Speed” or “Constant Pressure” system has quite a few years of history, yet they seem to be somewhat mysterious and ominous to many customers. In basic terms, an electronic controller, referred to as a “Variable Frequency Drive” or VFD (or simply “drive”) uses a pressure sensing transmitter to regulate the flow of water and keep that flow constant. As an example, if you had one of these systems installed in your home, you could turn on your shower and the system would immediately notice that there was a water demand to the system, thereby running the pump to ensure that the pressure stays constant. The controller would apply enough energy to the motor to meet that demand, nothing more. Once the demand of the shower was over, the system would shut down. If another source demanded water at the same time your shower is running, say your sprinklers, then the system would speed up the motor to increase the pumps output until the pump reaches its maximum output. There is no lag in water as it is all controlled via electronics.
There are many benefits to using a drive system. First, most homeowners can say “goodbye” to the larger tank they’ve been accustomed to. VFD systems usually don’t require large tanks or even medium sized tanks in most situations. You only need a very small 2-6 gallon tank to keep pressure in the line and for the initial burst of water before the drive ramps up. This save you money on initial installs and on future repairs because the tanks are far less expensive the smaller you go. Secondly, you save on power as the drive only instructs the motor to run at a certain speed, enough to meet the demand being placed for water. A side benefit of that is that the motor doesn’t run when there’s no demand or run at full speed when it’s turned on saving and hopefully increasing the life of the motor and pump. There’s also no more delays in receiving water or no surging, just a constant flow.
Almost any system you can build can be turned into a constant pressure/variable speed system. In most cases, the motor would have to be capable of having a 3-Phase 230V input which is why you would want to decide on this type of system before you did this initial pump installation (ideally) or when you have to replace a pump when it goes out. Most sub-division pressurized irrigation systems have these controllers to save money on power and to extend the life of the pumps and motors. In larger systems, they can control multiple pumps and bring them online as the demand for water increases, or take them offline as the water demand reduces.
As an authorized installer of drive systems, Burgess Pump prides itself working with the best controllers in the business. Quality drives from manufacturers such as ABB, Gould’s BF Series (now 3AS), Grundfos’s CU Series and Franklin’s Sub-Drive series offer our customers many choices for their drive needs. Give us a call and let us know what your requirements are. Our expert technicians will let you know what options you have and if a drive system is right for you. We’ve installed these systems for clients with large pressurized irrigation systems using several hundred horsepower motors down to clients with small residential 3/4HP systems. Let us take the guesswork out of designing your system.