Westinghouse Type KR, Installation & Operating Instructions Manual

Page: 86 / 124

trans mission line is flowing out of the line section
being protected. Conversely, when fault power is
flowing into this line section, the control is such as
to block the transmitter and keep it from being turned
on by secondary functions such as sleet detection
and communication, should these functions be in use
at the s ame time. Should carrier be received from the
remote station, the hold coil and alarm coil will
energize through transistor
Q-7 in the receiver.
When carrier start operation occurs, the CARRIER
START c ontact opens applying a positive voltage
(see Figs. 16 and 17) to terminal 15 of the carrier set.
This puts a potential on the driver stage in the trans­
mitter and also appli es proper bias for the power
amplifier.
When a c arrier stop operation occurs , the
CARRIER STOP contact closes, which removes B+
( terminal 15) from the driver and the power amplifier
stages in the transmitter. CARRIER STOP , terminal
18, on the c arrier set is permanently connected to
terminal 14, for K-DAR and GCY relaying.
2.
HZM Relaying ( Fig. 15)
The control of the carrier set is effected by the
CARRIER START and the CARRIER STOP contacts.
These contacts are shown in their normal standby
condition.
The HZ-HZM relays operating from the voltage
and current on the transmission line, detect and
determine the direction of a line fault and thereby
control the c arrier transmitter and receiver.
The control of the carrier set is such as to start
the transmission of catrier when fault power on the
transmission line is flowing out of the line section
being protected. Conversely, when fault power is
flowing into this line section, the control is such as
to block the transmitter and k eep it from being turned
on by s econdary functions such as sleet detection
and communication , should these functions be in use
at the same tim e. Should c arrier now be received from
the remote station, the hold coil and alarm coil will
energize through transistor
Q-7
in the receiver.
When carrier start operation occurs , the CARRIER
START contact closes applying the full battery
supply voltage to terminal 15 of the carrier set. This
puts a potential on the driver stage in the transmitter
and also applies proper bias for the power amplifier.
6
When a c arrier stop operation occurs , the
CARRIER STOP contact opens. This applies a
positive voltage (see Fig. 15) to terminal 18 which
blocks the driver stage and the power amplifier stage.
It is possible under certain conditions that the
signals from two transmitters, attempting to block a
third receiver, would be of such amplitude, phase and
frequency as to .cause the RRH coil current to
"pulsate" . It would then be possible to have a false
trip.
In the case of the KR set for relaying 3-terminal
lines, the transmitter frequencies ( to avoid this pos­
sibility of false trip) should be separated by 100
cycles. All receivers and one transmitter would be
for the desired center frequency. One of the other
transmitters would be 100 cycles above, the other
100 cycles b elow this center frequency.
I N S T A L L A T I O N
G e n e r a
I
Upon receipt of a unit, whether shipped separately
or in an assembly , an immediate inspection should be
made. Carefully check for damage or shortages .
For necessary clearances and mounting dimen­
sions, see the following illustrations:
Flexitest Case Mounting . . . . . . . . . . . . . . Fig. 1
Sleet Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . Fig. 9
C o n ne c t i on s
External
The external connections will vary slightly de­
pending on the application, but in g eneral will be
along the lines described as follows : ( Refer to the
Schematic Diagram, Fig.
2. )
Terminals 1 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ground
12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coaxial Cable
13 and 19 . . . . . . . Supervisory Preference
Contacts
14 . . . . . . . . . B- "CARRIER STOP" return
15 . . . . . . . . . . . . . . . . Battery positive through
carrier start contacts
16 . . . . . . . . . . . . . . BattE)ry positive for alarm
cutoff ( used with com­
munication)
17
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-
18 . . . . . . . Carrier Stop for HZM Relaying
19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B+
20
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Relay Coil
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