Air Liquide Electrical Inspection

Air Liquide Production

Providing customers with industrial gas and energy solutions that are vital to their own industrial production is our priority. Whether their production is metal, chemistry, refining or energy.

Job Description:

Equipment & Points Measured Details:

Switch Gear 22kv

Know Your Equipment:

1- Ultrasound Equipment: UE Systems up 15000

2- Thermal Imaging Camera: Flir T Series

How Ultrasonic Electrical Inspection works ?

Partial discharge/tracking, arcing and corona all produce ionization which disturbs the surrounding air molecules. An Ultraprobe detects high frequency sounds produced by these emissions and translates them (via heterodyning) down into the audible ranges. The specific sound quality of each type of emission is heard in headphones while the intensity of the signal is observed on a display panel. These sounds can be recorded and analyzed through ultrasound spectrum analysis software for diagnosis & reporting.

Normally, electrical equipment should be silent, although some equipment such as transformers may produce a constant 50 cycle hum, or some steady mechanical noises. These should not be confused with the erratic, sizzling frying, uneven and popping sound of an electrical discharge.

Before beginning any inspection of electric equipment, be sure to review your plant or company’s safety procedures. We scan the equipment with the Ultraprobe and because of the characteristics of Ultrasound can pinpoint the location of discharge quite fast & easy. When it is not possible to get close to the test equipment, such as for safety reasons or while inspecting over-head power lines, use a parabolic microphone. UE Systems has two models, a parabolic dish – the Ultrasonic Waveform Concentrator (UWC) and the Long Range Module (LRM). These highly sensitive, directional sensors double the detection distance of a standard scanning module and provide pinpoint accuracy.

For more accurate diagnosis, ultrasound spectral analysis software helps identify sound patterns related to electrical emissions through spectral (FFT) and Time Series screens. Some of the more advanced instruments have on-board sound recording while others have on-board spectral analysis screens to help provide a diagnosis on the spot. \

22kv Mv Sg Unit (No Action Required)

6.6kv Mv Sg Unit (No Action Required)

22 Kv Mv Ring Switch (No Action Required)

ASU (Check The Connections Immediately)

Spectralyzer FFT View

Spectralyzer Time Domain View

There is a big difference in timed events and amplitude in the ‘time series’ and the sound is what I would expect to hear with tracking. There is a ‘popping’ noise along with ‘crackling’ noise which would lead me to suspect tracking.
The FFT is also showing peaks at first then basically fairly flat which again I would expect to see with tracking.
Although you may just see nothing as it may be early stage tracking.

Electrical discharge in the form of corona and tracking has caused numerous shut-downs and serious damage in Switch Gears. Because corona and tracking conditions are voltage problems that rarely produce heat, they go undetected during a typical infrared inspection. Fortunately, the combined use of ultrasound and infrared when performing a switchgear inspection will provide early detection of both heat and non-heat producing problems. With regards to ultrasound for electrical inspection, ultrasound can be used prior to opening any electrical switchgear or cabinet to complement the widely-used infrared instruments.