Southern States Smart Tap - Manual (Page 3)

A P P L I C A T I O N G U I D E
> Directional Fault Sensing > Smart Tap
APPLICATIONS
Substations and
Switching Stations
Manual and Remote
Controlled Switches
Circuit Switchers
Low current faults can trip the breaker and be cleared on the instantaneous
reclose operation. Smart Tap detects the direction of these faults and provides
information to the investigative team on the section where the fault occurred. The
detection of the direction of these kinds of faults is very sensitive due to pre-fault
compensation. Small changes in ground current are detected and the direction of
the fault is calculated. This information is not reported unless the substation circuit
breaker trips and a momentary outage exists.
FAULT SENSING CHARACTERISTICS OF SMART TAP
Over current faults can be detected with sudden changes in line current. Pre-
fault compensation allows the over current set points to be set incrementally above
the short term average load current. These direction indications are only reported if
the substation breaker trips out the line.
Smart Tap detects the direction of low current fauts with
the use of pre-fault compensation system which enables
the detection of faults with magnitude less than the current
unbalance in the network.
Smart Tap can work with a variety of current sensing devices.
Conventional CTs and the SSIPower CMD
® II can be used up
to 362 KV. Line post sensor devices can be used at 46 KV and
below.
Smart Tap does not require the use of high voltage PTs to find fault direction. Voltage synchronization can
be from any AC power source
CMD ® II Line Post Sensor CT
SSIPOWER SENSORS AND AUTOMATION