Report of Investigations 8257: AC Impedance Measurements Used to Locate Faults in Mining Power Cables

Details

• Personal Author:
  Conroy, George J. ; Hammer, Richard
• Corporate Authors:
  United States. Bureau of Mines
• Description:
  Various alternating current (ac) methods can localize faults in mining power cables. Several methods considered by the Bureau of Mines in this report are the murray loop for short circuits, wherein a bridge provides proportional distance to the fault; capacitance measurements for open conductors; inductance measurements for shorted conductors; phase comparison, high speed recordings of voltage and current in the faulted state are compared with normal voltage and current with the difference being a function of impedance change and impedance change being a function of fault location; and standing wave measurements, detecting the resonance of the length of cable to a fault (either short or open). Portable capacitance bridges are presently available for the second method, and the fourth method is well developed for use on large power distribution systems. Because it utilizes pulses rather than ac, the time domain reflectometer (tdr) method of fault locating was not included in this investigation. However, a comparative evaluation between this versatile method and the murray loop might prove advantageous in locating high resistance faults. [Description provided by NIOSH]
• Subjects:
  Electricity Mining Occupational Health Safety
• Series:
  Mining Publications
• Subseries:
  Report of Investigations
• ISSN:
  1066-5552 (print)
• Publisher:
  United States. Bureau of Mines
• Document Type:
  Text
• Genre:
  Case Report
• Rights:
  Public Domain
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  PRC - Pittsburgh Research Center
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  28 pdf pages
• NIOSHTIC Number:
  nn:10001158
• NTIS Accession Number:
  PB-275815
• Citation:
  NTIS: PB 275 815; :1-19
• Federal Fiscal Year:
  1977
• Peer Reviewed:
  False
• Source Full Name:
  NTIS: PB 275 815
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:29aa1d8a8b44cfc6b1dad3b1289eda6513561bad7b06b418e813683ee3361c43c83b6fe54dd11f94fd913c679bcd25d774916412eb215efc55b27228012b90b3
• Download URL:
  https://stacks.cdc.gov/view/cdc/201717/cdc_201717_DS1.pdf
• File Type:
  [PDF - 898.81 KB ]