The dynamics of determining a “good” filtration system’s mechanical design & installation can be challenging. Partly, because of the sheer number of determinants that need to be factored into the process. When designing, we find that the most straight forward approach is to prioritize components and needs. Typically, number one on this list will be the filter type itself or the filter pump in the mechanical pump room. If either fail, the entire system is down. This means that these selections are critical and any ancillary equipment to aid in serviceability and life expectancy are important.
Protecting the filter pump is absolutely critical and we do this by utilizing our Accupump System that includes VFD (Variable Frequency Drives) protection in all of our designs and installations. This protection and general energy savings inherent to VFD technology ensures you get the most life out of filter pump and exponentially increases the ROI of the equipment installation.
What is a VFD?
A VFD is a 3-phase induction A.C. motor controller that allows a pump to run at varying rates of speed, by varying a specific volts to hertz ratio applied to that motor. VFDs go by a few other names, including:
- Variable speed drive
- Adjustable frequency drive
- Adjustable speed drive
- Inverter drive
VFDs run an electric current through a series of transistors used as “switches.” These switches determine the frequency of power supplied to the motor and therefore determine how fast the motor will run. VFDs can be used wherever a motor’s output needs to be adjusted according to an input.
At a water filtration facility, for example, the speed of the motors on the plant’s filtration pumps will need to be adjusted depending on how much demand there is for water. If there is a constant flow into the pump, but decreased demand for water leaving the plant, a VFD can be used to slow the pump down and prevent too much water from entering the tank.When paired with automated control systems, VFDs make it incredibly easy to operate pump motors efficiently.
The Benefits of VFDs
There are two main areas where VFDs benefit you in the long run:
- Money and energy savings
- Extending the life of your motor
Some pump systems will have the motor running at full speed all the time, placing maximum demand on the system when it doesn’t need to exert that much power. VFDs allow a motor to change its frequency depending on the load it has to deal with. In water systems, that’s the amount of water. In A/C units, that could be the electrical load being demanded from the A/C unit’s motor to cool a home.
Because the motor can wind down when demand is low, it isn’t operating at maximum capacity all the time and burns less energy. This saves, what can amount to an extreme amount of money in the long run, especially if you’re running a water park, treatment plant, or factory with multiple motors as part of a large-scale operation.
Commercial and industrial facilities are subject to a utility demand charge based on the peak amount of energy they consume every month. It basically amounts to a surcharge for maintaining a constant flow of electricity.
VFDs make a motor use less energy overall, thereby reducing a facility’s peak demand and utility demand charge. There are also often government incentive programs available for businesses that install VFDs since they save so much energy.
Reducing Wear and Tear
Motors that don’t use a VFD can place unnecessary wear on their parts by having a “hard start/stop”. A large amount of current (called the inrush current) will slam the motor all at once in an attempt to overcome the initial inertia of being at stopped condition.
VFDs, on the other hand, allow a motor to ramp up its speed until it reaches peak capacity. That also means it takes less energy to get the motor started. For water pump motors, it also eliminates “water hammer,” in the mechanical system as well from being inundated by too much water at once. This saves life expectancy of other system ancillary components as well.
The VFD’s we use for our Accupump system have a variety of fail-safes built-in to protect the motor from damage in the event of a power dip or a failure in another part of the system. If the pump experiences a dip in power or error caused by faulty wiring, the system will send an error and cut power to the pump before it sustains extensive or catastrophic damage.
We take this a step further by using a Proportional Integral Derivative (PID) loop in conjunction with a VFD for our Accupump systems. Water pressure and filter cleanliness are monitored by the system, which automatically adjusts the horsepower of the pump to meet the designated flow required.
As the filter clogs, the pump’s speed is raised to maintain the flow until the filter is replaced/cleaned. In doing so, the Accupump’s enclosed control system utilizes the least amount of energy to meet your system’s designed flow rate at all times
Find Out More
Com-Pac has been designing, manufacturing, and installing high-end systems for almost 40 years here in Jacksonville, Florida. If you’re interested in finding out more about our Accupump system, give us a call or email us today.