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Distinguishing Motor Starts from Short Circuits Through Phase-Angle Measurements.

PB97156723

Publication Date	1997
Personal Author	Yenchek, M. R.; Cawley, J. C.; Peterson, J. S.; Kohler, J. L.
Page Count	20
Abstract	The Pittsburgh Research Center conducted an investigation to improve electrical safety in coal mines through research into short-circuit protection of mine power systems. Distribution voltage, transformer impedance, power center location, and motor size were found to critically influence the magnitude of short circuits and motor starts on high-voltage longwalls. The need for accurate and rapid fault detection was confirmed through computer models of power systems. Voltage and current waveforms of mine induction motors were recorded during field tests, and their salient characteristics were evaluated.
Keywords	Mine safety Motor starters Short circuits Coal mines Dust explosions Induction motors Power supply circuits Electrical faults
Source Agency	National Institute for Occupational Safety and Health
Corporate Authors	National Inst. for Occupational Safety and Health, Pittsburgh, PA. Pittsburgh Research Center.
Document Type	Technical Report
Title Note	Rept. of investigations/1997.
NTIS Issue Number	199715

Distinguishing Motor Starts from Short Circuits Through Phase-Angle Measurements.

Distinguishing Motor Starts from Short Circuits Through Phase-Angle Measurements.
PB97156723

Publication Date	1997
Personal Author	Yenchek, M. R.; Cawley, J. C.; Peterson, J. S.; Kohler, J. L.
Page Count	20
Abstract	The Pittsburgh Research Center conducted an investigation to improve electrical safety in coal mines through research into short-circuit protection of mine power systems. Distribution voltage, transformer impedance, power center location, and motor size were found to critically influence the magnitude of short circuits and motor starts on high-voltage longwalls. The need for accurate and rapid fault detection was confirmed through computer models of power systems. Voltage and current waveforms of mine induction motors were recorded during field tests, and their salient characteristics were evaluated.
Keywords	Mine safety Motor starters Short circuits Coal mines Dust explosions Induction motors Power supply circuits Electrical faults
Source Agency	National Institute for Occupational Safety and Health
Corporate Authors	National Inst. for Occupational Safety and Health, Pittsburgh, PA. Pittsburgh Research Center.
Document Type	Technical Report
Title Note	Rept. of investigations/1997.
NTIS Issue Number	199715