A Sprint Electric drive saved the day for a customer who was experiencing problems on extruding lines because of a tripping DC drive. The machine was nearly 20 years old and had been reliable until the spurious tripping grew more frequent.
The customer, after replacing everything associated with the Siemens DC drive, contacted our technical services department for help. The fault was diagnosed over the phone to be an internal power supply issue and the north east based customer was offered two options:
Even though the second option was more expensive, the customer chose it because minimising downtime was crucial. The company knew of the reliability and cost effectiveness of Sprint’s product from other machines it had. The job was completed on time and production was reliable once more. In the event of similar drives failing on other machines, the faulty Siemens drive was inspected for repair as a spare.
Engineers in our electro-mechanical team succeeded in servicing two inverter-driven 250kW fan motors within three working days. The units had been subject to periodic vibration analysis by a fan manufacturer and had begun to show bearings faults long before they were close to failing.
They were used in a machine that toughens glass by quickly heating and cooling it, a process known as quenching. The machine was critical because each piece of glass produced goes through this process. Downtime causes huge tailbacks, letting down customers, so reliability is paramount.
As the building had been built around the fans, removal would not be easy. The task involved uninstalling the motors from the application, removing them with specialist lifting gear and servicing them at our Huddersfield Service Centre to SKF Certified Rebuilder standards.
Reinstallation, including laser alignment of couplings and a full production test, followed. During the repairs, our engineers noticed that the inverter-driven motors had no insulated bearing or housing to protect against currents passing through the bearings, which could damage them over time.
The issue was discussed with the customer and an SKF Insocoat insulated bearing was fitted to both non-drive ends of the motors to increase the life of the bearings and improve the machine’s reliability. The work, carried out by five Westin Drives engineers, was completed ahead of schedule, resulting in production being restored to peak performance and reliability.