Abstract: Method and apparatus for identifying and determining the energization status of a cable having a conductive neutral member and an internal resistive screen layer involving probes radially movable relative to the cable to contact the neutral member and the internal resistive screen. Narrow-band AC signals and resistance measurements are utilized for self-testing and for cable testing. A microprocessor controls probe-heating in the advancing of probes through plastic sheath to reach the neutral wire and resistive screen layer. Resistance measurements made under control of the microprocessor are monitored with probe advance. Oscillators provide two signals of different frequencies, one of which is that of the power being transmitted through the cable, to provide distinctive signals indicative of cable energization status.

Abstract: A method and system for determining the status of power distribution cables which involves the removal of a plug from the sheath which is tiny relative to the size of the cable to expose an area of resistive material which may be probed to detect the presence or absence of a signal of predetermined frequency. The apparatus is equipped with self-testing circuits as well as circuits for determining resistance between the resistive layer and the sheath, whereby positive identification of the cable to be tested is assured. The apparatus is clamped directly to the cable and is controlled from a remote location, which protects the operator of the equipment. The plug removed from the sheath is cut and extracted by a tool which is also subject to remote control by the operator.

Abstract: Disclosed is a tamper-proof device for fastening a sealing collar. A hard metal tab engages a slot in the head of a bolt and prevents the bolt from turning, thereby preventing removal of the sealing collar. The device also provides means which prevent removal of the hard metal tab.