Westinghouse KD Instructions Manual

K-DAR DIRECTIONAL COMPARISON
I NT RODU CT ION
This leaflet describes the overall functioning
of K-Dar relays when used in conjunction with a
blocking channel (power line carrier, microwave or
pilot wire). Detailed description of operation,
as well as setting and maintenance recommendations
for individual relays of the K-Dar directional com­
parison blockiug system are covered in the individual
relay instruction leaflets; the des.eription here is
intemted to supplement these relay instructions.
A PPLIC AT ION
Dir. e ctional comparison blocking is employed to
eliminate delayed clearing of end-zone line faults;
thus, high speed, simultaneous clearing of all line
faults is accomplished.
with current and potential from the protected line
are unable to trip both selectively and at high speed
for line faults near the remote station. By transmitting
a signal from the remote station when the fault is
external to the protected line, the local relays are
blocked from tripping.
means of intelligence, local relay tripping must be
delayed for internal faults near the remote station,
to insure against undesired tripping when the fault
is on an adjacent circuit near the remote station.
This system can be utilized with minor differ­
ences with either on-off or frequency shift type of
operation over pilot wire tones, microwave or power
line carrier channels .
Blocking of tripping is ef­
fected by either keying on or shifting the transmitter
frequency.
EQUIPMENT
K-Dar is the designation for a group of relays,
which are itemized below:
Directional Fault Detecting Relays
1 -Type KD Directional phase tripping unit,
NEW INFORMATI ON
INSTALLATION
INSTRUCTIONS
BLOCKING SYSTEMS
Protective relays energized
Without this additional
COMPLEMENT
OPERATION
•
consisting of:
1 -Phase-to-phase
operates for all three combinations of
phase-to-phase faults anywhere on th e
protected line.
1 - Three-phase unit (ZP-3 ¢).which operates
for 3 phase faults anywhere on the pro­
tected line.
1 -Indicating contactor switch (ICS).
1 -Type KD-1 Directional Phase start unit, con­
sisting of:
1 - Phase-to-phase
reach in the reversed direction to that
of ZP-¢4.
1 - Three phase unit (Zs-3 ¢), set to reach
in the reversed direction to that of ZP-3 ¢.
1 -Indicating contactor switch (ICS).
1 -Type KRD (or KRC, or KRP, or KRQ) Di­
rectional ground tripping unit, consisting of:
1 -Directional unit, current polarized (D 0c )
1 -Directional unit, voltage polarized (D
1 -Instantaneous overcurrent unit ( 1 0 )
1 -Indicating contactor switch (ICS)
&
Auxiliary Relay Accessories
1 -Type KA Carrier auxiliary relay, consisting
of:
1 -Receiver relay unit (RR). with a holding
coil, RRH, a tripping coil, RRT. and two
contacts, RRG
1 -Phase auxiliary unit (CSP)
1 - Ground auxiliary unit (CS G)
EF F ECT IVE OCTOBER
41-911
I .L.
MAINTENANCE
•
unit (ZP-cfxh which
unit (Z&#). set
0p )
RRP
&
1959
to