It is estimated that £74 million of savings have already been made by using Variable Speed Drives and High Efficiency motors.

When building a new pumping system, most Pumps are selected with a “safety factor” for potential future uprates or to allow for wear in the pump or fouling of the system. Often there are many different parties involved in specifying and building a system and the safety factor can grow exponentially. This results in the pump delivering much higher flows than required. There may also be the need to vary the flow due to process conditions or varying heating and cooling needs within buildings.

Traditionally, throttling is used to regulate flow in a pumping system. While throttling reduces the flow, the motor is still running at full speed and works even harder as it has to work against a restriction. By reducing the speed of the motor, the variable speed drive ensures no more energy than necessary is used to achieve the required flow. A centrifugal pump running at half speed consumes only one-eighth of the energy compared to one running at full speed. This is because the torque needed to run a pump is the square of the volume. For instance, reducing the pump speed to 80% only requires 64% of the torque (0.8x0.8) (Tµn2). Furthermore, to produce 64% of the torque only requires 51% of the power (0.64x0.8) (Pµn3), as the power requirement is reduced in the same way. The explanation for this lies in the pressure difference across the impeller. When less pressure is produced, less acceleration of air or fluid across the impeller is required. It is the simultaneous reduction of acceleration and pressure that multiplies the savings. savings.

Utilising an Electrical variable speed drive is the simplest and most economical way of controlling the pump and matching it to the pump system. Download the Energy Savings Calculator which helps you work out exactly how much you can save by replacing a fixed speed damped or throttled centrifugal load with a variable speed drive controlled solution. Click here to download this file

Buy a Copy of the Europump Variable Speed Pumping - A Guide to Successful Applications in our shop                                                                                                                                                   

Or why not download a free copy of our Variable Speed Best Practice Guide.

This guide is the result of co-operation between three different industries whose goal was to produce a document that would clearly define; in simple terms the information required when planning to use an electronic Variable Speed Driven Pumping System. The guide focuses mainly on application within the Industrial Sector, however the principles used will be applicable to most pumping applications. Click here to download this file