DWP Services have been using a range of variable speed pump controller for many years. We have found many of them have some advantages and some disadvantages. Here we will discuss a few to give you some guidance on what can be used.

After some years we have narrowed down inverters keeping in mind cost and performance, here is a short guide.
Motor mounted and wall mounted inverters –

Grundfos MGE and Saver

Grundfos are the biggest pump company in the world. Their reliability cannot be beaten and the technology has clearly been heavily invested in. This ensures Grundfos stays as the household name of pumps and inverters bringing complete peace of mind. The main variable speed drives is the soon to be discontinued MGE inverter and the new Saver 1 and 2 inverter. The MGE inverter has a deep parameter list for a knowledgeable engineer to fine tune to the maximum for complete efficiency and peace of mind.  But on the other hand the MGE inverter will work with the right configuration file and basic set up. It may not be running to maximum efficiency but will deliver water where you want it year after year.

The Saver inverter is the newer edition to the Grundfos family, this has a hugely expanded menu giving the customer complete configuration. Reliability and quality has not been compromised and reliability is still at the top of its game.

Grundfos are notoriously expensive to their top end products but believe you get what you pay for, if you want a long term reliable solution this may be the manufacture for you.

Xylem Lowara Hydrovar

We are now on the 5th generation of hydrovar. The years have seen complete redesigns of the hydrovar inverter but in all truth the menu and performance values have not changed too much. If you have a hydrovar it is most lijeky its the 3rd 4th or now 5th generation. Luckily enough no matter which one of these you have you can now buy an inverter to communicate with any model through its compatability software. The hydrovar is a motor or wall mounted inverter that has a pump specific set up generally used for water boosting. The excellent mulit-pump communication RS-485 is a real game changer in the pump world due to its ability to constantly keep system pressure whilst adjusting parameters or switching between units. The Hydrovar is most definitely a highly regarded inverter in the market although fairly expensive.

Coelbo Speedomatic

DWP Services is a fan of the speedomatic water cooled inverter. These units are cost effective, user friendly and reliable. The speedomatic can supply up to a 10AMP water pump and has an integral pressure and flow sensor so no need for extra wiring. They may be made out of plastic and a little bulky but now come with a LCD backlight display and a Volt Free fault contact giving the customer the ability to install and alarm to the unit in fault conditons.

Nastec Vasco

We believe this is a strong competitor in the variable speed market. This unit is wall or motor mounted just like the hydrovar and is very cost effective. The menu system is easy to navigate whilst giving a huge amount of adjustable parameters


If you require technical advise or any more information on any of these products contact DWP Services now for expert advice.

Xylem 214

Differences between submersible and immersible pumps

The terms submersible and immersible sound similar, however, these two are strikingly different and I want to explain to you why.

Submersible pumps are a heavy-duty type pump for heavy-duty jobs. Immersible pumps are a more cost-effective option for lighter-duty applications in a nutshell but let’s delve into further detail.

Submersible Water Pumps

Submersible water pumps have many industrial uses. They are completely enclosed and the motor is integral with the pump which is designed to run continuously submerged in water.

Submersible pumps are built with frames that are precision machined to ensure a tight fit between every component of the motor and pump. Submersible pumps typically have a specially designed dual seal design where the outer seal is lubricated and the second seal is located in an oil bath chamber in, or below, the motor housing for seal lubrication.

Although built for continual submersion generally these water pumps can also be placed in dry environments that only flood under rare circumstances. Based on their design, the motor may require an external source of liquid for cooling or have an intermittent run time rating when run un-submerged.

These pumps are typically used in applications where they help manage things like sewage, storm & drainage water and oily water.

Immersible Water Pumps

Immersible water pumps have motors that are built with the intent that they may be submerged and continue running in the event of the rare flood. They are, however, not meant to be submerged under normal everyday circumstances.

These motors are built specifically to operate in a dry environment. They are built with a sealing system that can withstand being submerged under up to 30 feet of water for up to two weeks. Immersible water pump motors are designed with a drive endplate packed with moisture-resistant grease, instead of the oil chamber found in a submersible water pump.

Immersible water pumps are generally easier to service and are cheaper to operate and maintain than the aofrementioned submersible water pump. They are appropriate for use in underground storm water pump stations where the pump gallery is designed to function as an incidental secondary wet well for the very rare major flooding event. After this motor is immersed, it must be removed for inspection and a bearing change.

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