A solar water pumping application comes with a variety of accessories, all of which can be added to solar water pumping stations. From DC circuit breakers to remote monitoring systems, this short module will take you through the A to Z of accessories that Grundfos offers within the solar range. Let’s get started. 

First up, there's the DC circuit breaker. A DC circuit breaker is intended for SOLAR panels and its main function allows you to disconnect the power, so the panels can be operated safely during service. Furthermore, you can apply a DC circuit breaker on each string in a solar panel array – making it much easier to identify where the faults are, as you can disconnect one individual string to check wiring or other potential issues.

Next up, there’s the surge arrestor. This unit protects against nearby lightning strikes and thunderstorms – however, it does not protect against a direct hit by lightning. Due to its ability to protect against these natural weather phenomena, it extends the lifetime of renewable solar inverters, while at the same time protecting the solar panels.

Then, there’s a combiner box. The role of the combiner box is to bring the output of several solar strings together. Combiner boxes come in different shapes. One is a simple solution in which the wires are connected directly to the strings in the panels, while the other is more advanced and includes terminals, fuses, DC disconnection possibilities as well as the aforementioned surge arrestor to protect the box.

Then, there’s the sine wave filter. A sine wave filter is only for external frequency drives of 380 VAC or higher. It’s a crucial component as it prevents the motor from wearing out. 

This is because external frequency drives use pulse-width-modulation to create a sinewave form, which creates voltage and current spikes – causing the motor insulation to break. 

Thanks to the sine wave filter, the motor’s lifetime is extended, the system is subjected to less stress and noise is minimised.

Next up, there’s the dry-run switch. It’s important that the pump is always submerged in water. If not, there’s a high risk the pump will get damaged. The SQFlex has a built-in dry-run switch, but for the SP pump, you'll need an extra component to detect dry-running. If a dry-run situation is possible, we recommend that the pumps use a dry-run switch. 

By using a dry-run switch in a submersible pump, your system can detect when the water disappears or is lowered into the borehole. For a surface pump, we recommend using an ultrasonic sensor switch to detect water in the pipe.

Next, there’s galvanic protection, consisting of zinc anodes. They help prevent corrosion in the water. Furthermore, the small sacrificial anodes help protect against high chloride content – or brackish water. Based on the quality of the water, the zinc anodes should occasionally be replaced. 

Next, there’s the flow sleeve. A flow sleeve ensures that the motor is cooled. Such a sleeve is essential when water enters the borehole above the pump installation, as sand and silt is passed along the inlet of the pump. Without a flow sleeve, the sand and silt would enter the pump and cause damage. 

Next, there are the control boxes. The CU200 – which is the Grundfos SQFlex Control Box – allows you to add a float switch. When the storage tank is full, the flow switch signals to the CU200 to shut off the pump. 

Another possibility is the IO101 controller. This lets you automatically switch between solar panels and AC power in terms of operating your pump. Both controllers are specifically designed to operate with Sqflex, though the IO101 will also work with a CRFlex pump.

Finally, there’s the remote monitoring solution. And as solar installations are typically installed in remote places, you can’t always count on people being around to manually monitor and survey the system. Therefore, it’s particularly relevant to use monitoring solutions such as Grundfos Remote Management to monitor solar pumping stations. 

By doing so, you can get instant tangible information on the operation as well as trend curves, alarms and warnings. It allows you to react to any problems as well as minimise the amount of service visits.     

So, that covers the range of solar accessories offered by Grundfos, ensuring that you’re well-equipped when selecting accessories for solar pumping stations.