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with ultrasonic waves, the sensor needs to be close to the gap of the cabinet.
Ultrasonic signals are audible through digital filtering).
According to the regulations of the State Grid Regulations, refer to Table 2 to
determine the insulation status of the switchgear:
Ultrasound reading
Explanation
-6 ~ 0dBuV
,
No discharge sound
No partial discharge
0 ~ 6dBuV,a short discharge sound
There is a slight discharge of the equipment, you should
pay attention to it later
Above 6dBuV
,
discharge sound
The equipment has obvious discharge, which should be
combined with TEV test
Table 2
Note: the demarcation point (6dBuV) is slightly different in different regions. In
some regions (such as foreign countries and southern networks), 6dBuV is used
as the demarcation point. Above 6dBuV is judged as an obvious discharge
phenomenon, while users of State Grid generally use 8dBuV as the demarcation
point. Whether the final purpose of 6dBuV or 8dBuV is to predict the insulation
status of the switchgear, it is recommended to use 6dBuV as the demarcation
point, so that the operation status of the switchgear can be more early warning.
TEV measurement
If you need to use the built-in TEV sensor to measure the partial discharge of the
switchgear, just click the icon in the sensor type display area to switch to the TEV
sensor mode