DETECTION OF LOW-CURRENT SHORT CIRCUITS
Devices presently in use by the rail transit industry can adequately detect and respond to overload fault currents. Detection of less than overload fault currents is particularly difficult because the characteristics of such currents resemble characteristics normally associated with train or power switching operations. Consequently, trains may continue to operate until the fault current becomes large enough to be detected by overload devices or until the fault results in smoke and fire activity. The latter is particularly hazardous in tunnel systems. The objective of this research was to identify and provide preliminary evaluation of detection methods and equipment to enhance transit system safety through reliable detection of electrical faults that are not detected by circuit breaker overload protection. The Charles T. Main, Inc., researchers conducted an extensive survey of rail transit systems, electrical industry organizations, and electrical equipment supopliers worldwide to determine how the problem is currently being handled and to identify methods and equipment that may provide potential solutions. Information collected on the consequences of low-current faults did not identify evidence of highly dangerous incidents. Reports indicated damage to facilities and eqiupment and incidents of localized smoke and fire. It appears that several types of low-current fault detection devices are in use in countries other than the United States that could be adapted for use by transit systems in this country. Field testing, in cooperation with an electric rail transit system, is recommended as the next appropriate step toward improved low-current fault detection.
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Washington, DC United States 20001
- Sagar, N S
- Publication Date: 1984-12
- Media Type: Digital/other
- Features: Appendices; Figures; References; Tables;
- Pagination: 216 p.
- NCTRP Report
- Issue Number: 7
- Publisher: Transportation Research Board
- ISSN: 0732-4839
- TRT Terms: Circuit breakers; Instrumentation; Protection; Rail transit facilities; Railroad electrification; Rapid transit cars; Safety; Safety equipment; Short circuits
- Old TRIS Terms: Fault currents; Protective devices
- Subject Areas: Administration and Management; Highways; Maintenance and Preservation; Public Transportation; Railroads; Safety and Human Factors; Security and Emergencies; Terminals and Facilities; Vehicles and Equipment; I61: Equipment and Maintenance Methods;
- Accession Number: 00451143
- Record Type: Publication
- Files: TRIS, TRB
- Created Date: Nov 30 1985 12:00AM