UE Systems Ultraprobe 3000, Инструкция по эксплуатации

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Electric arc, corona, tracking detection
There are three basic electrical problems that are detected with the Ultraprobe 3000:
Arcing: An arc occurs when electricity flows through space. Lightning is a good example.
Corona: When voltage on an electrical conductor, such as an antenna or high voltage trans-
mission line exceeds the threshold value, the air around it begins to ionize to form a blue
or purple glow.
Tracking: Often refered to as "baby arcing", follows the path of damaged insulation.
Although theoretically the Ultraprobe 3000 can be used in low, medium and high voltage systems,
most of the applications tend to be in medium and high voltage systems.
When electricity escapes in high voltage lines or when it "jumps" across a gap in an electrical
connection, it disturbs the air molecules around it and generates ultrasound. Most often this sound
will be perceived as a crackling or "frying" sound, in other situations it will be heard as a buzzing
sound
Typical applications include: insulators, cable, switchgear, buss bars, relays, contactors, junction
boxes. In substations, components such as insulators, transformers and bushings may be tested.
Ultrasonic testing is often used at voltages exceeding 2,000 volts, especially in enclosed
switchgear. Since ultrasound emissions can be detected by scanning around door seams and air
vents, it is possible to detect serious faults such as arcing, tracking and corona without taking the
switchgear off line to perform an infrared scan. However, it is recommended that both tests be used
with en-closed switchgear.
NOTE: When testing electrical equipment, follow all your plant or company safety procedures.
When in doubt, ask your supervisor. Never touch live electrical apparatus with the Ultraprobe.
The method for detecting electric arc and corona leakage is similar to the procedure outlined in
leak detection.
Instead of listening for a rushing sound, a user will listen for a crackling or buzzing sound. In some
in-stances, as in trying to locate the source of radio/ TV interference or in substations, the general
area of disturbance may be located with a gross detector such as a transistor radio or a wide-band
interference locator. Once the general area has been located, the scanning module of the
Ultraprobe is utilized with a general scan of the area. The sensitivity is reduced if the signal is too
strong to follow. When this occurs, reduce the sensitivity to get a mid-line reading on the meter and
continue following the sound until the loudest point is located.
Determining whether a problem exists or not is relatively simple. By comparing sound quality and
sound levels among similar equipment, the problem sound will tend to be quite different.
On lower voltage systems, a quick scan of bus bars often will pick up a loose connection. Checking
junction boxes can reveal arcing. As with leak detection, the closer one gets to the emission site,
the louder the signal.
If power lines are to be inspected and the signal does not appear to be intense enough to be
detectable from the ground, use UE Systems
LRM (Long Range Module) which will double the
detection distance of the Ultraprobe and provide pinpoint detection. This
is recommended for those situations in which it may be considered safer to inspect electrical
apparatus at a distance. The LRM is extremely directional and will locate the exact site of an
electrical discharge.