In this study, experimental investigation has been carried out for the defect detecting capability of two different way of the OW (oscillating wave) voltage test, such as with-cable-charging and without-cable-charging method. For this purpose, two types of OW voltage tests have been performed at the laboratory on the 22.9 kV CN/CV cables in which artificial needle-type and knifecut-type defects were well integrated. Based on the test results, it could be remarked that the with-cable-charging method is more appropriate to the after laying test due to its consistency of the test condition regardless of the cable length under testing.