Power Transmission Engineering Magazine
www.powertransmission.com/articles/6420

Sulzer Doubles High Voltage Testing to Improve Repair Times

January 15, 2018
Performance testing of high voltage motors and generators is usually carried out to determine benchmark data following a major repair. However, increasingly, customers are requiring this information as part of a problem diagnosis or to verify performance figures for a component when its essential data has been lost. To keep up with growing demand, Sulzer has made a major investment at its Falkirk Service Center that will enable the test-bed load capacity to be doubled.

Until now, the Falkirk site has used a 1,250 kVA diesel generator that operates through two step-up transformers to provide 3.3 - 11 kV via high voltage switchgear to the test cell. This setup ensures a reliable power source for testing that is not affected by local demand on the power grid. The new investment by Sulzer will add a 2,000 kVA and a 700 kVA generator to the site that will be synchronized through a 4,000A LV switchboard, as well as a new 2,500 kVA transformer, that will double the capacity of the test bed.

2 MW load testing

The original capacity of the service center was 1,000 kW in load testing, of which 800 kW could be used for testing vertically-orientated motors, across a full range of voltages from 400 V up to 11 kV at both 50 and 60 Hz. The installation of the new equipment will increase the load testing capacity to 2,000 kW for horizontally-orientated motors as well an increase in voltage to 13.8 kV. The majority of the equipment tested in the additional capacity will be large, high voltage, AC motors, but the possibility to test DC motors up to 600 V, with a loading up to 800 amps will still remain.

Furthermore, an additional test-bed area is now in place to allow multiple motors to be tested alongside each other. This means that if the testing of one motor needs to be extended, it will not hold up other projects, allowing equipment to be returned to customers even more efficiently.

The new test bed offers customers the possibility of load testing generators using a slave motor to turn the generator and connecting the output to a load bank. In this way, generators that have undergone major repairs can be tested to ensure that they are fit for purpose before they are re-installed and recommissioned.

Improved customer experience

As part of this upgrade project, the test area is equipped with the latest monitoring controls and safety equipment that provide the test engineers with remote visualizations of the sensor readings while protecting them from large pieces of rotating equipment. A customer viewing area is also available, from where owners of equipment can watch and interact with the test engineers to ensure that the entire process is transparent and straightforward.

Marc Stuart, assistant general manager, at Sulzer’s Falkirk Service Center comments: “In the past, only equipment that had undergone a major repair would have received a full-load performance test. Now, more and more customers are requesting full-load testing following an overhaul, giving them complete peace of mind that the equipment is fit for purpose.

“Our customers are now able to see their motor operating at full load and can review a complete set of test results, including vibration analysis, partial discharge, motor current signal analysis (MCSA) and other condition monitoring data. This is providing our customers with confidence, not only in the performance of the motor but in the service solutions they are receiving. A full test report can then be issued, providing a baseline set of data that they can use once their equipment is installed and running in its application," added Stuart.