How soft starters are shredding supply costs
Instead of forking out to upgrade a local sub station, a shredding company is using soft starters to overcome the problems of limited supply capacity and high peak demand charges
The company's business has grown rapidly, resulting in heavy investment in new equipment. However, this has not been without its problems.
The electrical supply to Evergreen's premises is provided by a local substation with limited capacity. The ramifications of this became evident during start-up of the company's two shredders. High current surges were dimming the lights, not only of Evergreen's own premises, but also of neighbouring units. And Evergreen was incurring high peak demand charges.
Eco-friendly solution sought
The scale of the charges prompted the company to look into the uprating the sub station - but this would have been too costly, at around £30,000, and it was not in keeping with the company's environmental stance.
Engineers from Fairford Electronic carried out tests on a range of electric motors at Evergreen's Avonmouth site. The two-part tests involved fitting Fairford Startmaster soft starters to a number of auxiliary motors, and a QFE soft starter to the large shredder motor. The tests were positive, revealing that the StartMaster units reduced current surges at start up.
Similarly, the QFE soft starter resolved the problem of high in-rush current on the large shredder motor.
It also provided a solution in situations where the shredder jammed and had to be reversed. Also, the QFE unit realised energy savings, typically 1kW, due to its ability to optimise when running lightly loaded.
The total cost of providing the soft-starter systems to Evergreen was less than 25% of the £30,000 required for uprating of the sub station.
"We are delighted with the solution provided by Fairford, not only on the grounds of cost, but also because it is environmentally sound," said Jeff Rendall, business advisor to Evergreen.
"Our business is heavily environmentally related, so a solution which means that we can use the existing power supply provision is very much in keeping with the spirit and the ethos of our operations."