Abstract
The detection of high impedance
faults on electrical distribution systems has been one
of the most persistent and difficult problems facing
the electric utility industry. Recent advances in
digital technology have enabled practical solutions
for the detection of a high percentage of these
previously undetectable faults. This paper reviews
several mechanical and electrical methods of
detecting high impedance faults. The significance of
these previously undetectable faults is that they
represent a serious public safety hazard as well as a
risk of arcing ignition of fires. High impedance faults
produce current levels in the 0 to 50 ampere range.
Typically, HIF exhibits arcing and flashing at the
point of contact. Throughout the utility industry,
there have been differences of opinion on how often
HIFs occur. Normally, utilities do not keep good
records on the number of down conductor instances.