Energy Saving

Energy Saving

With rising energy costs, products offering energy savings are becoming increasingly important. To help businesses reduce energy usage, Fairford have developed a range of energy saving products.

The vast majority of electric motors in use today are fixed speed, fixed voltage AC induction motors.  These motors consume two thirds of the total electricity used in industry. With this in mind, using a technology that could save energy on fixed speed induction motors should be a consideration when replacing motor starters or designing new systems.

Energy recovery with Internal bypass as standard


iERS is our patented energy saving system with a combined internal bypass to save energy on lightly loaded motors. iERS reduces the voltage and current supplied to a lightly loaded motor to only allow the motor to consume the exact amount of energy required to maintain the speed at that load. When the motor is at full load the internal bypass reduces the losses produced by the control element. This combined approach enables iERS to save more energy in more applications than any other competing technology.

iERS has been market proven over the past 10 years and has now reached its latest development realising even greater savings. Applications such as fans, pumps and chillers can typically see savings of around 8-40% of total energy consumption.

How it works

Fairford’s energy saving system works by reducing the current and iron losses of a motor not running at full load. The energy savings will depend on a number of factors including the efficiency of the motor and the load.

Fairford Soft Starters will also save businesses money by reducing the electrical and mechanical strain placed on applications – resulting in less ‘down time’ and maintenance cost on electrical circuits, gearboxes, belts and associated mechanical components.

iERS is a technology that monitors the voltage, current and power factor during the start of a motor and then uses this information to ensure the motor runs efficiently under all load conditions.

iERS - How It Works

When any AC induction motor becomes lightly loaded, the power factor and the efficiency decrease. This is caused by the inherent design of the motor and the laws of physics, and leads to energy being wasted. These are known as excitation losses.

iERS continually monitors the power factor, recognizing when the motor is becoming lightly loaded and then instantly employing strategies to reduce the losses by controlling the voltage and current supplied to the motor to match the load conditions. This not only increases the part load power factor, but reduces the energy consumption in kW.

When the motor becomes fully loaded, the power factor increases, and iERS automatically bypasses itself to ensure the most efficient use of energy in all motor load conditions.

See this example of the energy savings that could be made using Fairford’s energy saving system:

90kW Motor Running at 100% Load
90kw motor running at 100 percent load


90kW Motor Running at 20% Load
90kw motor running at 20 percent load


90kW Motor Running at 20% Load with energy saving motor controller
90kw motor running at 20 percent load with energy saving motor controller

Savings Calculator
The annual savings amount that could be achieved for a 1.8 kW per hour reduction is shown in this table.

The price of electricity is calculated using a value of £0.13 per kWh.

% Time
Part Load
Annual Hours
at Part Load
kWh Saving Annual Saving
40% 3,494 6289 £818
60% 5,241 9434 £1226
80% 6,988 12578 £1635

The above is a worked example; every application is different and will generate different levels of savings.

With a range of products from PFE to centris, Fairford offers a solution for every motor starting application.

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