During the operation of high voltage rotating machinery, the high voltage stator insulation systems will be subjected to several thermal, electrical, ambient and mechanical stress which are all together acting as a “TEAM” in order to deteriorate the insulation materials. Examples of these stresses are uncontrolled electric fields, heavy vibrations, external contamination; loose wedges or a bad performance of the field grading system.
All problems mentioned above will result in partial discharges occurring within the insulation system. Those partial breakdowns will easily “consume“ the insulation materials and the bounded epoxy resin until a final breakdown appears. So, partial discharges are not only an indicator but also a result of dielectric failing. Therefore dielectric testing is a necessary tool for the assessment of the insulation system its condition.
Maintenance Partners is equipped to offer a wide range of measurements to determine as well the surface condition as the quality of the components of the stator insulation systems. As well off-line and on-line testing are possible, even continuous on-line monitoring is possible.
• Winding resistance measurements
• Impedance tests
• Surge testing
• Insulation resistance test
• Polarization index test
• Step-voltage test
• Dielectric absorption test
• Tangent delta and capacitance measurements
• Partial discharge analysis
• Hi-pot test
Except the stator winding assessment, Maintenance Partners also offers the necessary tests and inspections to perform insulation condition measurements on salient pole and turbo rotors and stator core insulation systems.
• Recurrent surge oscillation measurements
• ELCID core tests
Electrical Analysis
Maintenance Partners offers the measurement of the electrical behavior of rotating machinery during operation at different loads, cost-up and cost down. We are equipped with an 12-chanel digital oscilloscope and the necessary probes to measure parameters like voltages, currents, load, and power factor. Besides Motor current analysis on squirrel cage motors is possible to asses the condition of the rotor cage and the rotor bars.