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Energized Testing & Electrical Signature Analysis (ESA)

What is ESA?

Electrical Signature Analysis (ESA) is an energized test method where voltage and current waveforms are captured while the motor system is running, to assess the health of the motor. Energized testing provides valuable information for AC induction and DC motors, generators, wound rotor motors, synchronous motors, machine tool motors, and more.

How does it work?

All ESA systems require motor nameplate information of voltage, running speed, full load current, and horsepower (or kW). Optional information including 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 gearbox application - can be entered for a more detailed and accurate analysis.

A Fast Fourier Transform (FFT) creates the spectral display, and the algorithms perform a spectral analysis on voltage and current waveforms to detect faults related to incoming power, the control circuit, the motor itself, or the driven load. These can then be trended for condition-based maintenance and predictive maintenance purposes.

The key difference between Motor Current Signature Analysis (MCSA) and ESA is with MCSA the FFT is done on the current waveform only, not the voltage. This makes it more difficult to easily distinguish incoming power related problems from motor and driven load problems. With ESA you have both the current and the voltage FFT on the same screen, so it’s just a matter of comparing the voltage and current FFT spectra to determine the source of the fault.

Why is it important?

Finding a motor fault before it breaks can save your organization countless hours of downtime and thousands of dollars in savings, justifying itself immediately. Our ESA tester is actually 2 instruments in 1 - a complete Power Quality (PQ) Analyzer and a complete Motor Analyzer (ESA). When in PQ mode it can be used for energy data logging, harmonic analysis, voltage and current charting, viewing waveforms, waveform capture of sags and swells, transient capture, and event capture.

ALL-TEST Pro offers unmatched motor testing technology. Our instruments are portable, safe, and easy-to-use - allowing you to evaluate equipment in the field, shop floor, or at a service facility. Save yourself hours that might be spent on troubleshooting - or, better yet, save yourself catastrophic damage and costs due to motor failure. Learn more about our full line of ALL-TEST Pro products.

Successful Applications Using ESA

  • AC/DC Motors

  • VFD Applications

  • Generators

  • Traction Motors

  • Machine Tool Motors

  • Gearboxes

  • Pumps and Fans

  • For Reliability Testing

  • For Commissioning Testing

  • For Troubleshooting Testing

  • For Energy Evaluation​


Application Success Stories

Hear first-hand examples from our customers on how energized testing saved them time and money:

Fan Motor Test Reveals Damaged VFD, Prevents Safety Hazard & Process

Energized Motor Testing Reveals Improper VFD Settings

Electrical Signature Analysis for Power Plant Pump Performance Assessment


Read All Case Studies

Energized Testing FAQs

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