Thank you for your question...

Puncture test means whether the the product-under-test can endure the high potantial voltages between two conductive near-by but not contacted.
It is usually tested under AC voltage, and the tested result is pointed on
leakage current while the voltage is applied.

And the test voltage of the hipot generally comes from the formula

Vt = (Vo * 2) *1000 V

when Vt means test voltage of the hipot tester
Vo means operating voltage of the product-under-test
For example, if the operating voltage of the product-under-test is 220V AC,
the test voltage of the hipot tester must set on AC 1440V.
.....and...the test time is 1 min at least.