This installation of a 315kW inverter is probably the world’s largest single-motor retrofit to an injection moulding machine. The Windsor press has a clamping force of 2200t, was built in 1974 and continues to operate with its original controls and motor.
With four other machines this is part of a 3rd phase of installation for the moulding company, whose investment in SyncroSpeed started in 2010. Following successful results with other machines, CCS were asked to survey their largest, oldest press and submit an assessment of the probable energy savings that could be achieved and the likely costs of a retrofit system to deliver the results. A full consideration had to be given to engineer appropriate solutions for the abnormal features of the project such as the large, old motor to be driven by an inverter, and the interface to the controls, mainly cascade relay logic, mechanical timers and potentiometers.
SyncroSpeed installation was completed over three days and the machine returned to full production. Software commissioning brought the entire machine cycle into motor speed control using a range of strategies to derive the appropriate motor speed at any instant. The SyncroSpeed control software has continually developed since its launch in 1999; the current version continually monitors the host machine status and adjusts motor speed around 50 times every second. The refinements are such that every opportunity is taken to reduce motor power consumption without compromising machine productivity or part quality, no matter how old or recent the host machine’s control format or hydraulic configuration.
As the snapshot reveals, the initial results are very encouraging and in-line with expectation; the motor power was reduced from 147.7 kW to 109.3 kW, a saving of 26%. Most of this energy is no longer heat generated in the machine’s hydraulic oil and so power is also removed from the cooling tower operation that is necessary to prevent the oil from overheating. In all this saving of around 40 kW will reduce the energy bill by around Eur 35,000 which will total to Eur 1/4 million over the next 7 years.