Diagnostic testing and monitoring of rotating machines
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Diagnostic testing and monitoring of rotating machines

Know the condition of your machine for reliable operation Reducing the risk of failure in rotating machines Rotating machines, such as motors and generators, are highly important components in power generation and industrial applications. Machine reliability and availability are therefore in high demand. Premature failure may lead to significant economical losses, due to unexpected outages and possible damage to the asset itself. To plan maintenance effectively, it is essential to have accurate condition information about when components need repairing or replacing. Negative influences on...

A variety of electrical tests can be performed over the complete life cycle of your machines to increase their reliability, prevent premature failures and to extend reliable service life. Off-line diagnostic tests provide you with a snapshot of current condition and detect possible defects. Temporary and permanent on-line monitoring enable continuous condition assessment under normal operating conditions. Testing and corrective measures to ensure machine reliability and extend life expectancy > Regular or continuous condition assessments using various electrical diagnostic methods > Reverse...

Rotating machine parts and recommended electrical tests Detecting faults to prevent failure Electrical diagnosis testing can tell you a lot about the condition of a motor or generator. Electrical tests are commonly done after the machine has been manufactured, installed on-site or during periodic maintenance checks. The electrical tests listed here are diagnostic methods that allow the reliable condition assessment of insulation and other components in rotating machines. Machine part tested The results of these measurements give you an indication about when you should perform maintenance on...

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The ideal solution for your individual machine testing needs Recommended diagnostic tools For common diagnostic methods on rotating machines, we offer the matching testing or monitoring solution. Together, these solutions allow you to perform a thorough condition assessment of electrical machines in order to quickly identify potential problems and risk of failure. Electrical test Capacitance, dissipation factor (tan δ)/ power factor measurements Partial discharge (PD) measurement On-line PD monitoring Voltage withstand testing Insulation resistance, polarization index and dielectric...

Portable on-line PD measurement and temporary monitoring system Permanentlyinstalled system for continuous on-line PD monitoring of generators and motors Light-weight testing device for dielectric response analysis on highvoltage assets Sweep frequency response

Capacitance, dissipation factor (tan δ)/power factor measurements Why measure? Which part can be tested? ü Stator winding Rotor winding Capacitance (C) and dissipation factor (DF/tan δ)/power factor (PF) measurements are conducted to identify defects, which affect the condition of the machine insulation. A healthy insulation is essential for safe operation. Variations in C and DF/PF over time are often signs of partial discharges (PD) or insulation degradation. The trend data assists in determining the speed of insulation aging and to identify critical changes that may require further...

>> A progressive increase of the DF/PF in the curve during the tip up test can be an indication of ongoing PD activity. PD measurement is then recommended to determine the defect type and location. >> Portable high-voltage test source with C and DF/PF measurement capability up to 15 kV and 6A >> OMICRON recommends to test in an upwards and downwards ramp to give an indication of PD activity (inception and extinction voltage). >> Resonant circuit (CP CR600 and test capacitance) for testing at rated frequency >> DF/PF values can be compared to the manufacturer’s published >> Fast measurement...

Partial discharge measurement Why measure? Which part can be tested? Partial discharges (PD) occur in the insulation system of rotating machines, where the local electric field stress exceeds the local electrical strength. It causes a progressive erosion of insulation materials that can lead to their failure. ü Stator winding Rotor winding Compared with other dielectric tests on rotating machines, the differentiating character of PD measurements allows single weak points of the insulation system to be clearly identified. PD in rotating machines (e.g. slot discharges or end winding...

Good to know ... >> A combined measurement at the star point (when accessible) and at the terminals enables more detailed analysis. >> Low filter frequency measurements enable a larger coverage of the windings. >> Digital, frequency-selective PD measurement systems are robust against external noise and enable advanced diagnostic options. >> Advanced diagnostic tools, such as 3PARD (three-phase amplitude relation diagram) and 3FREQ (synchronous multifrequency measurements) are used to separate noise and multiple PD sources for more reliable interpretation. >> OMICRON suggests the use of a...

On-line partial discharge monitoring Why measure? Which part can be tested? Compared to routine off-line diagnostic tests, on-line partial discharge (PD) monitoring provides asset managers with continuous insulation condition status while motors and generators are in operation and under the influence of deteriorating forces. ü Stator winding Rotor winding Temporary PD monitoring is used to periodically observe changes in PD activity, whereas permanent PD monitoring continuously assesses PD activity over the entire service life of a machine. Based on the collected data, machine operators are...