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Applying a solidly grounded wire after hipot test

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    Applying a solidly grounded wire after hipot test

    Applying a solidly grounded wire immediately after performing a high-potential test:

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    Quote Originally Posted by epenland View Post
    Applying a solidly grounded wire immediately after performing a high-potential test:
    Will ensure immediate personally safety.
    Requires a rubber glove.
    May damage the test set.
    May damage the insulation under test.
    Is not necessary

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    Quote Originally Posted by akumaleon View Post
    Will ensure immediate personally safety.
    Requires a rubber glove.
    May damage the test set.
    May damage the insulation under test.
    Is not necessary
    I saw this question and answered "Will ensure immediate personally safety." I didn't see it show up in my wrong answers.

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    Quote Originally Posted by epenland View Post
    Applying a solidly grounded wire immediately after performing a high-potential test:
    The hipot test is a nondestructive test that determines the adequacy of electrical insulation for the normally occurring over voltage transient. This is a high-voltage test that is applied to all devices for a specific time in order to ensure that the insulation is not marginal.

    Hipot tests are helpful in finding nicked or crushed insulation, stray wire strands or braided shielding, conductive or corrosive contaminants around the conductors, terminal spacing problems, and tolerance errors in cables. Inadequate creepage and clearance distances introduced during the manufacturing process.

    Used the given blow link all information here !Thank You

    https://electrical-engineering-porta...-strength-test

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    Quote Originally Posted by khanhamza View Post
    The hipot test is a nondestructive test that determines the adequacy of electrical insulation for the normally occurring over voltage transient.
    This is a bit misleading, I would say a hipot can be a destructive test.

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    Quote Originally Posted by SecondGen View Post
    This is a bit misleading, I would say a hipot can be a destructive test.
    Agreed. For instance, A VLF hi-pot test is less destructive, but can still damage a cable if there is a pre-existing condition. A DC hi-pot test is a destructive test for cables, not only in bringing out a fault in a cable but also the adding stress on the cable itself.

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    Quote Originally Posted by darinlamos View Post
    I saw this question and answered "Will ensure immediate personally safety." I didn't see it show up in my wrong answers.
    I answered "Will Ensure immediate personally safety" and the answer was not correct.

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    Applying a solidly grounded wire immediately after performing a high-potential test:
    Your Answer: Will ensure immediate personally safety.
    Correct Answer: May damage the insulation under test.

    I cant find anything that supports this. Everything I read says ground it after....

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    Quote Originally Posted by bec51392 View Post
    Applying a solidly grounded wire immediately after performing a high-potential test:
    Your Answer: Will ensure immediate personally safety.
    Correct Answer: May damage the insulation under test.

    I cant find anything that supports this. Everything I read says ground it after....
    IEEE 400.1:

    4.1 Test precautions:
    Breakdown or terminal flashover may generate traveling waves up and down the cable that can be of a
    magnitude great enough to cause degradation of the insulation of the cable or accessories or breakdown
    of the cable insulation or the test source. A damping resistor or energy absorbing resistor in series with
    the output of the dc test source rated for the reflected test voltage and energy stored in the cable if a
    flashover occurs should be installed to isolate the dc test source from the test load. This resistor, if
    properly sized, may protect the test source from overvoltages by absorbing the energy in the test circuit
    and can reduce the oscillation amplitude of the traveling wave.

    3.2.3 Discharge resistor
    A resistor with a resistance not less than 5000 Ω/kV of test voltage is recommended to be used to discharge the
    cable system after testing. This resistor should be designed to withstand the full test voltage without flashover
    and to handle the discharge energy without overheating. An insulating grounding stick rated for the full test
    voltage and a flexible conductor should be provided to connect the resistor across the cable circuit and ground.

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    found it....

    400.1
    4.3 bottom of page 15 to top of 16

    At the completion of the test period, the voltage can be reduced by returning the voltage control of the test equipment to zero. The voltage on the cable will discharge through the internal resistance of the test equipment. Normally this resistance has a very high ohmic value and the discharge time will be very long, especially for cables longer than a few 100 m. A long discharge time may be impractical. Further, directly grounding the cable with zero resistance while the voltage is at an elevated voltage can damage the cable. in order to discharge longer lengths of cable safety, separate automatic grounding systems with built in high voltage discharge resistance designed to provide a time constant of several seconds or longer can be used. In all cases, discharge mechanisms should be designed to safely handle the test voltage and energy stored in the cable under test.

    After the test voltage is reduced to a low level, the high voltage conductor should be solidly grounded.

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