Why is a high voltage test conducted on wiring?

High voltage tests are done usually at the request of electrical engineers. When conductors are pulled into a conduit system, it is supposed to be done very carefully. In some instances this can not be done with out subjecting the conductors to mechanical stress. A high voltage test is applied to these conductors to make sure that the insulation factor of the wire has not been compromised. If the conductors do not pass the test, they have to be removed and new wire reinstalled.