DRIVES, MOTORS + SWITCHGEAR
motor to service. These had to be done with the customer’s express permission, since they were of necessity a com- promise – as was the case with the original manufacture of the motor. We welded new sections on the stator support structure, because we could not access many of the cracked sec- tions to weld them. After re-assembling the motor we ver- ified that the vibration had improved substantially but the resonance frequency was consequently located very close to the rated speed, due to the increase in stiffness we had added to the structure. On our test base we proved that with the resonance located lower than running speed no problems would occur on site, since the site base is more flexible than our test base. An offbeat add-on solution This being a compromise solution, we could not provide a 100% guarantee of reliability on the work done. The client asked if any further measures could be taken to assure a full guarantee of successful operation first time on site. In response we offered an offbeat add-on solution which, when tested and proven effective, enabled us to provide, with confidence, the assurance the client sought. The add-on solution entailed providing a made-to- measure removable 7.5 tonne mass of steel temporarily fitted onto the top of the motor. This mass further reduced vibration of the motor and lowered its resonance frequency by a small but sufficient margin to guarantee correct
Chargehand Alwyn de Bruin monitors the final tests on the 17 MW motor at M&C’s large motors test facility in Cleveland, after completion of repairs to the motor’s stator. operation on site. It was made removable because the customer wanted first to try running the motor without this additional measure. The success of our investigation and repairs was demonstrated when the motor was put into service after an unplanned breakdown. It operated with lower vibrations than it had operated at for over a decade – and this without the 7.5 tonne mass added! □
For more information visit: www.mandc.co.za
DRIVES, MOTORS + SWITCHGEAR : PRODUCTS + SERVICES
Innovation and growth in drive technology
Drive specialist NORD DRIVESYSTEMS continues on its course of growth. With innovative new products and com- prehensive investments – the largest to date in the com- pany’s history – it saw a close to 18% increase in sales for 2021, compared to the previous year. Additional advanced drive solutions are planned to be brought to market in 2022. Last year, the family-owned company based in North Germany launched four products that set new standards in the sector. The patented DuoDrive marks a new milestone. As an innovative geared motor which integrates the high-efficiency IE5+ synchronous motor into a single-stage helical gear unit housing, it sets new standards in terms of efficiency, installation space and version reduction. The new decentralised NORDAC ON frequency inverter and the additional sizes for the IE5+ synchronous motor and the NORDAC PRO SK 500P control cabinet inverter have been developed with the focus on customer benefit and energy efficiency, and ensure significant performance improvements in their areas of application. With the cancellation of most trade fairs in 2021, these new products have been presented only in digital form. In 2022, NORD DRIVESYSTEMS an- ticipates opportunities to stage live presentations. Last year, the company invested primarily in locations
The high-efficiency portfolio from NORD includes: the NORDAC ON frequency inverter, the integrated geared motor DuoDrive and the IE5+ synchronous motor. and logistics. Additional facilities were brought into opera- tion in Germany, Poland and the USA, and the starting sig- nal was given for a new production plant in China. Com- pletion of a new administration building at the company’s headquarters in Bargteheide is planned for this year. During 2021 NORD DRIVESYSTEMS also increased the number of employees in the NORD Group to around 4 700 and continued to focus on providing reliable support to customers, finding solutions, building its worldwide pres- ence and diversification across industries and regions. For 2022, the company is looking to grow further and to develop more new products in cooperation with its cus- tomers. For more information contact NORD DRIVESYSTEMS. Visit: www.nord.com
MARCH 2022 Electricity + Control
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