Grundfos offers a complete range of 3” and 4” submersible pumps for domestic groundwater applications – from the basic SP pump to the advanced SQE model. This tutorial offers a comparison of the pumps to facilitate selection.

The 4” submersible SPA pump is ideal for basic applications where there is a need for a hard-working, robust pump.      

The pumps are controlled by a simple on-off function. A pressure switch activates the pump if the pressure drops below, say, 2.5 bar and deactivates it if the pressure exceeds 4 bar.

For constant pressure regulation the SPA pump can be equipped with an external frequency drive – the Grundfos CUE. All SPA pumps are made entirely from stainless steel to make them corrosion-resistant and increase life.

The 3” SQ pump is controlled by the same on-off function as the 4” SP pump but features an innovative motor with a range of protection features. These include voltage handling, soft start, dry-running protection and overload protection, making the pump a robust choice.    

The compact 3” SQ pump obviously fits into boreholes the same size or bigger but is also a great replacement alternative in original 4” boreholes where sediments over the years have narrowed the hole.

Now, let’s take a look at the most advanced submersible pump solution for domestic applications – the SQE.

Besides having all the advantages of the SQ pump, the SQE is equipped with a variable speed drive allowing the pump to adjust its speed according to demand. This means that regardless the number of opened taps the pump will deliver constant pressure.  

The SQE is also one of the easiest pumps to install thanks to the all-in-one constant pressure installation kit, making it a popular choice among installers.  

So, whether you are looking for a submersible pump for a remote holiday cottage where the pump is at work only 4-5 times a year or a busy family home Grundfos’ pump range covers your needs.