This guide covers the diagnostic testing of new or service-aged installed shielded power cable systems, which include cable, joints, and terminations, using partial discharge (PD) detection, measurement, and location. Partial discharge testing, which is a useful indicator of insulation degradation, may be carried out on-line or off-line by means of an external voltage source. This guide does not include the testing of compressed gas insulated systems or continuous on-line monitoring at normal service voltage.