Examples: Using Ultrasound and Infrared for Electrical Inspections

Ultrasound and infrared technologies are a perfect match when conducting inspections of electrical equipment. At any voltage, thermal anomalies and sources of ultrasound such as tracking and arcing can occur. Corona can also occur at 1000 volts and greater. Any of these conditions threaten the reliability of the equipment being inspected.

Examples: Using Ultrasound and Infrared for Electrical Inspections

Typical electrical components that can be inspected with ultrasound and infrared include:
• Switchgears
• Load interrupter switches
• Breakers
• Transformers
• Motor control centers
• Terminal transition cabinets.
As a further complement to infrared inspections and to aid in the proper diagnosis of the condition, recorded ultrasounds can be seen in both FFT and Time Wave Form from a spectrum analysis software - this will show how to properly diagnose electrical anomalies. This form of analysis is referred to as ultrasound imaging.

Ultrasound and Infrared: Some Examples

1. 2000 amp main braker

1.amp_main_braker

1. 2000 amp main braker

The image above is a 2000 amp main breaker. Arcing was detected on the B Phase line side.  The arcing heard was worse when the load increased.  The arcing has severely deteriorated the internal contacts, and eventually will become do deteriorated that the voltage and wave form will be unable to reach the load.  At this particular facility, the replacement cost for this item is approximately $20,000 USD.

The Time Wave Form from the recorded ultrasound shows characteristic patterns of arcing – changes in amplitude and a loss of well-defined 60Hz harmonics

 

2. 2000 KVA 11KV-415v cast resin transformer

The next example is from a 2000 KVA 11KV-415v cast resin transformer.  An inspection on this equipment was requested after audible noise in the area increased, so the operators knew something has changed for the area to become louder.  The inspection was done during the winter months, and for this facility, this transformer typically sees a reduction in load as it supplies chillers and associated other plant equipment that normally does not work as hard during the winter months.  During the inspection it was noted that the load was around 420 Amps per phase.

2_sound_recording_amp_uk

Images of the 2000KVA transformer.

timewave1

Time Wave Form of recorded ultrasound from this transformer showing characteristics of arcing.

5_sound_recording_transformer_good

Time Wave Form of another 2000KVA transformer in the same facility showing normal ultrasonic noise for this type of transformer

2. Contactor

The next example is from a contactor on a piece of equipment called an orbit motor.  A routine airborne ultrasound inspection was done, and distinct sounds of tracking were heard.  A follow up inspection with infrared was performed, and the diagnosis was severe tracking. 

5
Time Wave Form view of the recorded ultrasound of this contactor show distinct signs of severe tracking and early stages of arcing

Conclusion

Ultrasound instruments are versatile and easy to use, and can greatly enhance inspections on almost any electrical equipment.  In the end, it’s all about safety.  Ultrasound inspections can be done prior to opening the energized gear to scan with infrared.  If an ultrasonic emission is heard, then the proper precautions can be taken before opening the energized cabinet.  Also, for those that rely on the services of an outside contractor to perform infrared scans, an ultrasound scan can be done in between the annual infrared scan to see if any emissions are heard. 

When ultrasound and infrared are used together, an inspector is given a greater chance of detecting anomalies that could potentially be missed when relying on just one single technology.  For best results, analyzing recorded ultrasounds in either the FFT, or time wave form view is the recommended method of diagnosing electrical anomalies heard with ultrasound.

R&D | 29.3.2018

Latest articles

Research report: Predictive Maintenance 4.0

A growing number of companies want to use big data analytics in their predictive maintenance and are also investing in the resources needed for this. Of the companies already using this technology, no less than 95 percent say that they have already achieved concrete results. This is the conclusion of a follow-up study conducted by PwC and Mainnovation among 268 companies in the Netherlands, Germany and Belgium.

Asset Management | 17.1.2019

12 Helpful Tips for Doing IT Service Desk

Over the years, the evolution of technology and the adaptability of the people to it, has been increasing drastically. This process has brought about a boom in the service sector, making the IT subunit of it, the most successful.

Cmms | 27.12.2018

It’s About “Time”

At Bentley Systems, we have been talking to our users, especially owners, and it has become clear that despite our collective best efforts, there is a gap in the market.  Owners need easy access to real-time, accurate, engineering information and they need tools that make it simple to keep engineering data up-to-date, especially those engaged in brownfield and revamp projects.  It takes too much time and effort to gather and verify the information they need to make decisions effectively. And for older plants that do not have 3D models, there is simply no visual way to verify and check information easily.

Partner Articles | 10.12.2018

How to Choose an Air Compressor, According to Science

Buying an air compressor, for the first time, can be challenging in many ways. There is a lot going on behind this power tool that offers faster and more efficient performance. Before we get to know about the details of an air compressor then, let’s understand how it works. How do air compressors work?

Applications | 10.12.2018

8 Ways to Identify and Eliminate Noise Hazards in the Workplace

Occupational noise hazards are one of the most common workplace safety concerns. Our hearing is sensitive and it does not take much to temporarily impair or permanently damage it. 

HSE | 10.12.2018

Bacterial Bandages, Natural Dyes and Recycled Fibres: Aalto Brings Materials Revolution to Slush

New materials play an important role in sustainable development and combatting climate change. New uses for old materials can also be a major industrial opportunity: for example, the value of biomass from forests in Finland can be doubled if used for manufacturing products of higher added value.

R&D | 4.12.2018

Maintenance: A Necessary and Important Function in the Future

Euromaintenance 2016 will take place in Athens at the end of May. It is the ideal moment to reflect on maintenance in a European context. Euromaintenance is known as the summit for all involved in maintenance across Europe, it’s the place to be. The conference, with the support of the EFNMS, is the only commercially independent conference covering the topics we deal with in the maintenance world.

EFNMS | 20.5.2016