(EN)
A high impedance fault isolation system (HIFIS) identifies, isolates and
dissipates
high impedance, low current faults which occur within an individual tap, or
branch,
of an electric power distribution system using only portions of the tap
affected. A
master meter, or father smart meter (FSM), on the affected tap sends a coded
signal
to an antenna receiver combined with a microprocessor and chip which operates
an
electromagnetic control (EMC) grounding spring switch which isolates the
downed
primary conductor by causing the distribution system protecting device, i.e.,
a high
voltage fuse or recloser, to de-energize the downed primary wire. This
localized
application of the HIFIS at the individual tap level allows the FSM to analyze
and
determine, for example, that the specific field condition is a "downstream
wire
down", and that the installed isolating device has failed to operate because
of
insufficient fault current, allowing the localized intervention of the HIFIS
to achieve
the de-energization more efficiently and safely, and within a much shorter
time
period. A fire door sensor circuit then receives the trip signal from the
microprocessor, causing the fire door sensor to melt open and release a
shorting
spring, in initiating operation of an expulsion fuse or recloser, which kills
the downed
live
wire.
