This equipment named
as POSITRON is used for detecting leakage in the
defective insulator in the string.
This equipment is
attached to hot stick & it is moved across each
insuator in the insulator string & it records
the electrical field surrounding the insulators.
The electrical field
surrounding an insulator decreases considerably
in front of a
defective insulator.
The downloaded data
gives us graphical presentation of the field against
each insulator of the complete string, enabling
us to identify the defective insulator.
The software data
analysis eliminates the need for operator interpretation.
B) By Voltage Measurement
Method
In this method the
voltage difference across each disc is made use
for measuring the leakage current in m A by connecting
galvanometer in shunt
If an insulator becomes
weak or gets punctured thevoltage difference across
that disc becomes zero and the care of that voltage
is taken by adjacent discs.
The punctured insulator
is identified by sudden deep in the galvanometer
and indicates its replacement
Punctured Insulator
Detector
Positron Make Electric Field
Measurement Type Instrument
Ritz Make Voltage Measurement
Type Instrument
Graph Showing Condition
Of The Insulator String By Positron Method.
Disc Insulator No.4 In
The String Is Defective.
Graph Of Healthy
Insulator String.
Advantages of PID testing.
No outage, so no interruption
to consumers
No revenue loss
Problem is highlighted
immediately, hence further breakdown may be avoided.
Emergency outage is
avoided
Contaminated disc
insulators can be cleaned by hot line washing, so
flashover of disc insulators resulting in to break-down
can be avoided.
PID Testing
