Variable frequency drives (VFDs) are now widely used for irrigation pumping applications due to the many cost saving opportunities they provide. Here, we look at the top three benefits irrigators can take advantage of by installing VFDs on irrigation pumps.
Energy savings through system flexibility
One of the major benefits of VFDs is that they can be programmed to run the pump at a certain speed and flow rate.
This is beneficial for agricultural irrigation systems that are zoned by field type, crop type, crop maturity and elevation, and can require different flow rates.
In the past, irrigators needed to size the pump for the worst possible case, and then use a combination of valves to try to run the system at the best efficiency point (BEP).
However, it is difficult to meet the BEP in all zones this way, so there are inevitably always zones where the pump is oversized, resulting in increased wear on the system, higher energy consumption and higher costs.
VFDs allow irrigators to customise the way the system runs so that pump speed will slow down, and flow and pressure reduced to operate a smaller zone at the BEP.
This has long-term benefits as there will be less system maintenance required, equipment will have a longer lifecycle, and energy costs will be greatly reduced.
Reduced water loss
By ensuring pumps operate at the optimum pressure for the irrigation application, VFDs have cost and environmental saving benefits for water.
If an irrigation system is operated with more pressure than required, sprinklers will mist which creates smaller water droplets through the nozzle that are more easily moved by the wind and evaporated into the atmosphere.
This results in a loss of water as it is less likely to reach the crop.
VFDs also allow irrigators to adjust pumps to automatically suit conditions so that water is not unnecessarily delivered. By doing this, scheduling is improved, rootzone waterlogging is avoided and there is no water wastage.
These have the added benefits of increasing the chances for higher crop production and reducing energy costs.
As well as lessening wear to equipment due to operating outside of BEP and higher pressures than necessary, VFDs also have other features that help to further reduce maintenance costs and increase the lifecycle of pumps.
VFDs are soft-start devices so problems associated with waterhammer and excess power draw during start-up are eliminated, and flow or pressure surges are reduced. This decreases wear, particularly on bearings and seals.
The Franklin Electric advantage
Franklin Electric’s line of VFDs – DrivE-Tech – was designed and developed to optimise, control and protect pumping systems, and is compatible with different types of pumps, including vertical multistage, centrifugal and submersible.
It can be used for water supply and irrigation applications, and is suitable to operate most new or existing systems up to 15kW.
The DrivE-Tech enclosure is manufactured from die-cast aluminium, and is sturdy, lightweight, easy to cool and compact in size. The panel has a IP55 rating, so it can be installed in humid and dusty places.
It has a display placed on top of the device and a buzzer in case of an alarm to help to operate the VFD efficiently and easily.
DrivE-Tech Solar is also available for efficient pumping and movement of water using the sun’s energy to generate DC power from solar arrays which is then converted to AC power to operate the electric motor of a new or existing above or below ground water pump.
It has an enclosure rating of IP65, with an aluminum body and 304SS metal parts.
The DrivE-Tech Solar constantly adapts pump speed to the available solar irradiation to maximise the amount of pumped water and allow continued operation even in low irradiation conditions.
It also offers operation of 3 phase 230V or 400V motors to power pumps with motor needs up to 15kW–30 amps maximum.
The knowledgeable team at Franklin Electric can help you find the right VFD for your installation to make sure you’re getting the most benefit from it.
This partner content is brought to you by Franklin Electric. For more information, visit https://franklin-electric.com.au/.