In a recent posting Lionel ZS6DPL uploaded two videos to the Amateur Radio 101 Telegram group. Lionel explained what his work entails and how he uses a spectrum analyzer to test electrical motors.
Now what is a spectrum analyzer?
A spectrum analyzer measures the magnitude of an input signal versus frequency within the full frequency range of the instrument. The primary use is to measure the power of the spectrum of known and unknown signals. The input signal that most common spectrum analyzers measure is electrical; however, spectral compositions of other signals, such as acoustic pressure waves and optical light waves, can be considered through the use of an appropriate transducer. Spectrum analyzers for other types of signals also exist, such as optical spectrum analyzers which use direct optical techniques such as a monochromator to make measurements.
By analyzing the spectra of electrical signals, dominant frequency, power, distortion, harmonics, bandwidth, and other spectral components of a signal can be observed that are not easily detectable in time domain waveforms. These parameters are useful in the characterization of electronic devices, such as wireless transmitters.
The display of a spectrum analyzer has frequency on the horizontal axis and the amplitude displayed on the vertical axis. To the casual observer, a spectrum analyzer looks like an oscilloscope and, in fact, some lab instruments can function either as an oscilloscope or a spectrum analyzer. More on spectrum analizers can be found HERE.
The following is a short overview of testing electrical motors:
There’s a huge range of diagnostic tools available for pinpointing motor issues — clamp-on ammeters, temperature sensors, Meggers, winding analyzers, spectrum analysers and oscilloscopes, just to name a few. And depending on the specific area of trouble, each tool can help illuminate the problem in different ways.
A good rule of thumb for troubleshooting a motor is to first rely on your senses: Is the motor hot or overheating? Does it smell or sound unusual? Is it physically behaving in an erratic way? To begin an evaluation, check in first on the basic measures of motor performance: current levels, power, voltage, and resistance.
Preliminary tests are generally done using the ubiquitous multimeter, which can provide diagnostic information for all kinds of motors.
There’s a huge range of diagnostic tools available for pinpointing motor issues — clamp-on ammeters, temperature sensors, Meggers, winding analyzers, spectrum analysers and oscilloscopes, just to name a few. And depending on the specific area of trouble, each tool can help illuminate the problem in different ways.
A good rule of thumb for troubleshooting a motor is to first rely on your senses: Is the motor hot or overheating? Does it smell or sound unusual? Is it physically behaving in an erratic way? To begin an evaluation, check in first on the basic measures of motor performance: current levels, power, voltage, and resistance.
Preliminary tests are generally done using the ubiquitous multimeter, which can provide diagnostic information for all kinds of motors.
Complex, powerful tools, electric motors are critical components in a wide range of equipment and tools, from the smallest electronic fans to the largest manufacturing and industrial equipment. Without motors, many basic industrial functions would be severely compromised, if not impossible; motors are the heartbeat of daily work.
Motor failure, therefore, can be extremely costly and disruptive, resulting in unscheduled downtime and unplanned maintenance costs. But by dedicating time to thorough motor testing — both in regular, routine maintenance programs and at the first sign of trouble — motor issues can be reliably predicted, prevented, isolated, and resolved with minimal service disruption.
Below are the two videos that Lional provided of the type of work he is doing and how he uses technology to to assist him in fault finding. Lionel thank you very much for the videos and a look in how you can analyze electrical motors before running into serious failures and high replacement costs.
I trust that our readers will find this technology article interesting. I did and learned several new things that I did not know before.
