Grundfos produces a variety of products for solar water pumping systems. In this training module, we’re going to take you through the main features and benefits of Grundfos’ products that are applicable with solar pumping systems.

Our primary points of focus will be the SQFlex submersible pump, the CRFlex surface pump and the MGFlex motor. We will also take a brief look at the RSI solar inverter. In order to create a steady, understandable flow throughout the module, we’ll focus on each product one at a time. Let’s start with the SQFlex.

The Grundfos SQFlex is a submersible pump range with a built-in drive, enabling it to be used in solar water pumping systems and in AC back-up applications. It’s by far the most popular Grundfos product when it comes to solar water pumping systems.
The SQFlex pump range is characterised by its environmental friendliness and its ability to efficiently make use of solar and wind energy.

The range consists both of helical rotor pumps and centrifugal pumps. In short, helical rotor pumps are for medium to high heads and low to medium flows, while centrifugal pumps are for shallow heads and high flows.

Let’s take a closer look at the SQFlex.

First of all, it has built-in electronics. These include a variable frequency drive, motor protection and a dry run sensor.

The variable frequency drive, for instance, can convert DC power from the solar panels into AC power for pumping. The built-in electronics ensure that the SQFlex can handle both AC and DC power, while it also results in easy installation of the SQFlex as no external components are needed for basic operation.

However, there is an option to use external control boxes, which only goes to show how flexible the SQFlex is.

Thanks to these built-in electronics, the SQFlex shouldn’t be thought of as just a pump, but rather a complete intelligent system.

Another advantage is the low operating cost thanks to the use of solar energy sources. Add to that the low level of maintenance, and you’ll soon notice that the total life cycle costs are significantly lower than in other water supply systems, once again showing the economic efficiency of solar-powered water pumping systems.

SQFlex is designed for both continuous and intermittent operation and it can be used in a variety of application areas. It is especially suitable for supplying water in remote locations, but it can also be used in commercial buildings such as schools or hospitals, farms, ponds, lakes and in conservation areas.

Imagine that you’re selling a SQFlex solar solution to a farmer looking to provide water for his livestock. Regardless of the location, depth to water and the volume of water required, the SQFlex can be customised to specific needs. That way, the farmer has a solution created specifically for his operation, while he is also ensured a reliable supply of water.

Additionally, the built-in motor protection and dry run protection of the SQFlex will remove any potential worries that the farmer may have about reliability and pump operation, giving him peace of mind.

Next, we’re going to shift our focus to surface pumps – more specifically, the Grundfos CRFlex. In connection with this, we’re going to show you how the Grundfos MGFlex motor utilises solar power for applications in which a CRFlex is typically used.

The MGFlex motor has been developed by Grundfos specifically to be used in surface pump applications using solar power. Its integrated variable frequency drive enables the high-efficiency permanent magnet motor to run over a wide speed range.

This allows the MGFlex motor to provide the CRFlex surface pump with the necessary power to be used in remote, rural applications including irrigation, livestock watering and water supply in remote villages.

But it can also provide power to CRFlex pumps in domestic buildings in rural areas or towns. Relevant applications in this respect include an indoors pressure-boosting system, ensuring reliable pressure at the tap, or even swimming pool applications.

In many ways, the advantages of the CRFlex using an MGFlex motor mirror those of the SQFlex.
For instance, it can be tailored and customised to any application and local conditions, meaning that it is delivered as a plug-and-pump solution, which also ensures that it’s very easy to install. Its built-in protection features mean that it requires little maintenance. And finally, its operating costs are low, ensuring a highly-efficient pumping at a low cost.

Furthermore, the MGFlex is a versatile product that can be connected to a number of different pump types.

Finally, we’re going to take a brief look at the RSI – Renewable Solar Inverter.

The RSI is an external drive designed to convert the DC power output from the solar panel into AC power supply for pump operation. It is designed to work with a broad range of submersible and surface pumps. Solar water pumping systems using an RSI can run a Grundfos pump up to 250kW in size.

The RSI is one of Grundfos’ latest product offerings and can be used in both new solar installations and existing water pumping systems.

Additionally, it is extremely quick to set up and can be configured for a Grundfos pump such as SP, CR or NB/NK and other pump types in less than five minutes, demonstrating its flexibility and unmatched simplicity. All you need to do is confirm which pump type is in use and your RSI is up and running.  

So, that covers the basic features and benefits of the Grundfos SQFlex submersible pump, the CRFlex surface pump, the MGFlex motor and the RSI drive. Let’s recap the main advantages.

The SQFlex and CRFlex bring similar benefits. They both offer a reliable water supply, they’re easy to install and maintain and most importantly, they bring cost-efficient pumping every day.
The MGFlex is a versatile motor that provides solar surface pumps such as CRFlex with the necessary power to be used in a range of applications.

The Renewable Solar Inverter – RSI – is an extension to SQFlex and CRFlex. It can be connected to a vast range of Grundfos pumps, contributing to its overall flexibility.

To sum up, a solar power system using any of these Grundfos products ensures not only reliable operation, but also an energy-efficient and cost-efficient solution.