At office equipment manufacturer Ricoh’s Telford plant, a large number of Air Handling Units (AHUs), plus water circulation pumps and compressors, contribute to a utility spend of £1.25 million each year. Keen to reduce energy consumption, energy specialist, Andy Smith, trialled two ABB drives, one on a pump, the other on an AHU.
With favourable results, the company decided to evaluate all its possible motor driven applications.
Around 90% of the originally identified applications have now been retrofitted with ABB drives, with around 70 drives running a large variety of applications around the site. Average payback is around six months per installation.
As well as providing significant energy savings, the drives have enabled the company to gain better control over a number of processes. For example, in the laboratory, the properties of the manufactured toner are tested, and to achieve optimum test conditions the temperature and humidity values must be maintained at constant levels. Using an ABB drive to control the laboratory air flow ensured that temperature was controlled to within 0.5°C of the set point. A drive controlled humidifier ensured that humidity varies by no more than 1.5%. With the drive’s flux optimisation, even at 50Hz, with no speed reduction, this reduced the power consumption from 5.5kW to 3kW.
Running at 35Hz, the power consumption was further reduced to just 1.6kW, providing a payback of just three months.
As a result, the company is applying drives in other applications, including three to synchronise two conveyors with a 22kW plastic granulator that grinds plastic parts for recycling. Linked to a PLC, the granulator can be run on demand.
Additional benefits provided by the drive were the supervised relay output function, Modbus compatibility, which allows control and monitoring of applications over a PLC network, and an energy saving feature which puts the drive into ‘PID sleep’ mode whenever there is no demand from the process.