We depend on electricity for everything we do. Insuring we have a safe and secure electrical system is essential to productivity and personal safety. If one component within an electrical system fails, an entire plant may shut down, costing significant time and labor – sometimes as much as millions of dollars. More importantly, if an arc flash incident occurs, it may endanger lives and cause severe injury.

It is essential that managers and technicians routinely monitor plant electric equipment in order to catch any conditions that may lead to failure.

Preventing Arcing, Tracking, and Corona with Ultrasound

When electricity discharges from high voltage lines or when it jumps across a gap in an electrical connection, it disturbs the air molecules around it and generates ultrasound. Often this sound will be perceived as crackling or frying; in other situations it will be heard as a buzzing sound. When inspecting components such as insulators, cables, switchgear, buss bars, relays, contactors, and junction boxes, the three most common electrical problems, arcing, corona, and tracking can all be detected by ultrasound in time to prevent failure conditions from occurring.

Ultrasound combined with infrared technology, are the best tools to detect and prevent electrical outages and failures. Infrared can detect heat generated by arcing and in most instances tracking; it will not sense corona. Ultrasonic testing is often used for identifying tracking, arcing and corona. While infrared instruments will detect emissions related to heat, ultrasonic equipment detects high frequency components of ionization produced by these potential failure conditions. These instruments translate ultrasound by heterodyning (an electric translation process), these inaudible sounds down into the audible ranges. Specific sound quality of each type of emission is heard in headphones while the intensity of the signal is observed on a display panel. By listening for a crackling, frying, or buzzing sound, a user will be able to quickly locate the source of the potential problem area. Ultrasound then provides the ability to accurately analyze the emissions via spectral analysis software for accurate diagnosis.

Electrical Failure and Arc Flash Incidence – Detect, Determine, Prevent

In addition to the costs to the physical plant, we need to consider safety. Emissions such as arcing, tracking and corona all have the potential of producing an arc flash incident.

There are a reported 5 to 10 arc flash incidents occurring daily within industrial plants. According to the NFPA, arc flash is “a dangerous condition associated with the release of energy caused by an electric arc.” As an arc flash occurs, there may be up to 1 or 2 explosions within milliseconds, which can generate temperatures between 5,000 and 35,000 degrees Fahrenheit. The pressure wave from an arc blast has been compared to an explosion from a hand grenade. Put simply, arc flash can kill.

Due to these common conditions in almost every plant, it is essential that plant operations managers understand whether electrical discharges such as arcing, tracking, or corona are present. These discharges if left undetected, can become a source of an arc flash incident and lead to potential failure or worse, bodily harm. Ultrasound can help.

Electrical Inspection Tips and Tools

Below, you will find some simple tips you can apply today to enhance your electrical inspection program.

	Use complimentary technologies to detect the potential for failure such as infrared and ultrasound.
	Document everything. A method of recording all test data and a method for analyzing that data is critical to the success of any condition based program.
	Know your equipment. Voltage will impact your diagnosis.
	When scanning enclosed systems, scan around door seams and air vents with a rubber focusing probe.
	For totally enclosed systems, use the contact probe at 25kHz – touch the cabinet in line with electric components.
	Always think safety... wear appropriate PC’s .
	Become familiar with NFPA 70E Standard for Electric Safety in the Workplace and OSHA Regulations.
	When scanning open access equipment, use a parabolic microphone to assure a safe scan distance.
	Plan ahead – walk your inspection route before testing to note anomalies, safety issues, and to determine strategies of your test route.
	For more information on tips and tools to effectively detect the potential for electrical failure, click here.

Rely on Experts for Technology, Training and Support

Although there are several ways you can improve plant efficiencies today, the need for expert analysis and technology may be a necessary next step in eliminating the potential for electrical failure, lost productivity, and an arc flash incident.

To the left, you will find several resources to help you enhance your electrical inspection program. We've included a mix of technical articles, guides, and professional consultants. Don't' forget, UE Systems acclaimed training courses are available on site or at any one of our training facilities.