Cable neutral corrosion, Phase II. Outdoor high voltage and high current short circuit tests on single phase extruded dielectric primary distribution cables. Phase II: final report, December 1977

Technical Report · Thu Dec 01 04:00:00 EST 1977

DOI:https://doi.org/10.2172/5264017· OSTI ID:5264017

Bahder, G.; Martin, M. A.; Piccione, N.; Prime, Jr., J. B.; Silver, D. A.

Severe deterioration of the concentric neutral conductor as a result of corrosion presents a problem of serious concern to power and communication companies as well as to other utilities using direct buried metallic facilities. The objective of this project was to establish the performance of insulating-type and semiconducting jacketed concentric neutral cables in comparision with bare copper concentric neutral cable under fault conditions from the standpoint of transient voltage gradients developed in the earth. It was considered that data generated in this project could be employed as substantiation for a change in the National Electrical Safety Code to permit the use of jacketed concentric neutral calble in joint-random installation with communication cable in locations corrosive to bare copper. The tests encompassed staged and prestaged fault tests on direct buried, 15-kV and prestaged fault tests on direct buried, 35-kV crosslinked polyethylene insulated cables of various concentric neutral conductor designs without jackets; insulating and semiconducting jackets were included as dictated by good design practices. The fault on the 15-kV cables were performed at rated voltage to ground with symmetrical currents of 5 and 10 ka with a prescribed sequence of circuit breaker reclosures. The 35 kV cables were similarly tested at 10 kA only. The main conclusions were: bare and semiconducting jacketed cables exhibit essentially the same transient voltage gradients (touch-and-step voltages) when tested under similar conditions; cables with an insulating type jacket will yield higher touch voltages and lower step voltages than cable with bare or semiconducting jacket under equivalent circuit impedance and earth resistivities; and the voltage at the fault is determined by the supply voltage and circuit impedances and is a dominant factor in determination of touch-and-step voltages.

• Research Organization: General Cable Corp., Union, NJ (USA)
• OSTI ID: 5264017
• Report Number(s): EPRI-EL-619(Vol.2)
• Country of Publication: United States
• Language: English

Related Subjects

200301* -- Power Transmission & Distribution-- AC Systems
EHV & UHV-- (-1989)
24 POWER TRANSMISSION AND DISTRIBUTION
AC SYSTEMS
CABLES
CHEMICAL REACTIONS
CONDUCTOR DEVICES
COPPER
CORROSION
CORROSION PROTECTION
ELECTRIC CABLES
ELECTRIC CONDUCTORS
ELECTRIC GROUNDS
ELECTRICAL EQUIPMENT
ELECTRICAL FAULTS
ELEMENTS
EQUIPMENT
METALS
PERFORMANCE TESTING
POWER DISTRIBUTION
POWER SYSTEMS
POWER TRANSMISSION
SEMICONDUCTOR MATERIALS
TESTING
TRANSITION ELEMENTS
UNDERGROUND POWER TRANSMISSION