what is meant by dielectric breakdown ? where we using HV
test kit & what purpose?
Answer Posted / sri
High-voltage transformers contain oil as their insulating
dielectric. When a critical electric field is exceeded,
conduction paths grow at microsecond speeds through the oil,
in the form of branched trees, called streamers. These can
lead to destructive breakdown.
Above a particular electric field, known as the dielectric
strength Eds, the dielectric in a capacitor becomes
conductive. The voltage at which this occurs is called the
breakdown voltage of the device, and is given by the product
of the dielectric strength and the separation between the
conductors
The high voltage test (also called dielectric strength test
or hipot test) can be made in AC or DC. If the high voltage
test is made in DC, it is then combined with insulation ;
if the high voltage test is made in AC, it is then, this is
then, more stressful for the sample and made according to
the sketch below.
Measurement of high voltage test under alternating current
is performed using an alternating voltage (50Hz) adjustable
to an effective 50V to 1,500V. As is the case with direct
current, the high voltage test detects any sudden rise of
current up to a programmed threshold.
http://www.sefelec.com/en/high-voltage-test.php
purpose
to test the insulators for their effectiveness. normally
used for transformer oil testing purpose.
Is This Answer Correct ? | 3 Yes | 1 No |
Post New Answer View All Answers
I am having a 1500 KVA transformer whose secondary current is 2086A and my connected load is 1000 KVA, I am having 400 KVAR APFCR for PF improvement what ratio of CT should i install in LT EB Bus to get optimum PF improvement?
The screw thread commonly used for transmission of motion is one of the following types of threads
To prove the capacity of a 10MVA transforemr with 6.5% impedance by a short circuit test how much power is needed to inject an impedance voltage if we have to arrive for its rated current?
How many types of faults are there in 3 phase power system?
Who are the manufactures those manufacturing 3Cx2.5sqmm FRLS cables. I heard about FRLS technology adopted only in wires useful for wirings
what types of electrical & mechanical test conducted in switchyard?
regarding safety what would u consider the most important rules to observe when inspecting electrical equipment?
What is voltage divider rule?
how to calculate energy of 3-phase motor?
What does ampere turns shows?
What is the permissible limit of shaft voltage for 6.6 KV motors ? Why? Is there any standard is available?
If one tertiary phase i.e. R,Y or B is earthed of a loaded type tertiary delta connected (Without load)of a power auto transformer, what is its advantage/disadvantage?
which is chemical used as in ro water what is difference betweeen multi grade filter&dual media filter
Why ground terminal is used in pot meter 10k ohms
What is the purpose of stablization resistor in high impedance bus bar protection