Electromagnetic Interference (EMI) Monitoring FAQ

Is the data review a manual process, or is it automated?

The data collection process and assessment of the content within the time domain signals is automated by the Cutsforth™ system. Condition alarms can be set based on the type of signal, e.g., arcing or partial discharge, and the energy content in microvolts. Trend features are available for future trend analysis by subject matter experts.

What are some ‘rules of thumb’ suggesting which failures may be associated with each frequency?

The important aspect is understanding where the CT is placed, i.e., the generator or a transformer, and the content of the signal, for example arcing or partial discharge.

How is Partial Discharge Monitoring different than Electromagnetic Interference Monitoring?

Usually, Partial Discharge Monitoring uses capacitive couplers on bus work to detect changes in insulation status of windings. Additionally, many Partial Discharge systems measure the time difference between the arrival of signals to approximate the location where a partial discharge occurs. However, Partial Discharge Monitoring ignores other types of discharges, such as arcing and coronal discharges. EMI Monitoring detects partial discharge, as well as arcing, coronal and gap discharges, sparking, and other signals associated with other discharge events. These events occur through High Frequency Current Transformers that convert radiated or conducted RF signals emanating from the defects to current values that can be assessed for content and severity.

What are the benefits of continual monitoring over third-party annual monitoring?

Third-party vendors visiting plants on an annual basis are expensive and only capture a miniscule snapshot of the generator’s health. Whereas continuous EMI Monitoring is a one-time purchase. The system creates a power spectrum and time domain waveforms from thousands of frequencies, allowing plants to measure and archive data over time to form a more comprehensive view of your generator’s health. This option allows plants and companies ownership of their data without having to pay to access it.

How do I interpret the data once I have it?

With Cutsforth™ EMI Assessment Algorithm, plants are able to automatically categorize time domain waveforms to establish which failure modes are present. Cutsforth™ also offers access to Subject Matter Experts to assist in reading and analyzing data.

Do I need an outage in order to install the Cutsforth™ Electromagnetic Interference system?

No, EMI Monitoring is a non-invasive installation process requiring NO outages.