Energised Testing using Electrical Signature Analysis
Electrical Signature Analysis (ESA) is an energised test method where voltage and current waveforms are captured while the motor system is running and then, via a Fast Fourier Transform (FFT), a spectral analysis is done by the provided software. From this FFT, faults related to incoming power, the control circuit, the motor itself, and the driven load are detected and can then be trended for Condition Based Maintenance/Predictive Maintenance purposes.
All ESA analysis systems require motor nameplate information of voltage, running speed, full load current, and horsepower (or kW). Additionally, optional information such as rotor bar and stator slot count, bearing numbers, and information for driven load components, such as blade count for a pump or tooth count for a gear box application can be entered for a more detailed and accurate analysis.
Energised testing will provide valuable information for AC induction and DC motors, generators, wound rotor motors, synchronous motors, machine tool motors, etc.
ALL-TEST PRO ESA instrument is actually two instruments in one- a complete Power Quality Analyser (PQ) and complete Motor Analyser (ESA). When in PQ mode it can be used for energy data logging, harmonic analysis, voltage and current charting, view waveforms, waveform capture of sags and swells, transient capture, and event capture.
When in ESA mode, it will provide the analyst with information about incoming power, mechanical and electrical health of the stator, rotor analysis, air gap analysis, and analysis of the driven load (gear boxes, belted applications, bearing, etc).
The key difference between Motor Current Signature Analysis (MCSA) and Electrical Signature Analysis (ESA) is with MCSA the FFT is done on the current waveform only and not the voltage. This makes it more difficult to easily and quickly distinguish incoming power related problems from motor and driven load problems. With ESA you have both the current and the voltage FFT to see on the same screen. So it is just a matter of comparing the Voltage and Current FFT spectra to determine the source of the fault.
Successful Applications using ESA
- AC/DC Motors
- VFD Applications
- Traction Motors
- Machine Tool Motors
- Pumps and Fans
- For Reliability Testing
- For Commissioning Testing
- For Troubleshooting Testing
- For Energy Evaluation