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and communication, should these functions be in use
at the s am e time. Should carrier be recei;yed from the
remote station, the hold coil and alarm coil will
energize through tran si st or Q-7 in the receiver.
When carrier start operation occurs, the CARRIER
START contact opens applying a positive voltage
(see Figs. 4 and 5) to t erminal 15 of the c arri er set.
This puts a potential on th e driver stage in th e trans
mitter and arso applies proper bias for the power am
plifier.
When
a
c arri er
stop
CARRIER STOP contact closes, which removes B+
( terminal 1 5 ) from the driver and the power amplifier
stages in the transmitter. C ARRIER STOP , terminal
18, on the c arrier set is p ermanently connected to
terminal 1 4 , for K-DAR and GCY relaying.
2. HZM Relaying (Fi g.
The control of the carrier s et is effected by the
CAR RIER START and the CARRIER STOP contacts .
These contacts are shown i n their normal standby
condition.
The H Z-HZM relays operating from the voltage
and current on the transmission line,
determine the direction of a line fault and thereby
control the carrier transmitter and receiver.
The control of the carrier set is such as to start
the transmis sion of catrier when fault power on the
transmission line is flowing out of the line section
being protected.
Conversely,
flowing into this l i n e section, the control is such as
to block the transmitter and k eep it from b eing turned
on by s econdary functions such as sleet dete ction
and communication, should these functions be in use
at the same tim e. Should carrier now b e received from
the remote station, the hold c oil and al arm coil will
energize through transistor
When carrier start operation occurs , the CARRIER
START
contact
closes
supply voltage to terminal 15 of the carrier set. This
puts a potential on the driver stag e in the transmitter
and als o applies proper bias for the power amplifi er.
When a car ri er stop operation occurs, th e CAR
RIER STOP contact opens . This applies a positive
voltage (see Fig. 3) to terminal 18 which bl ocks th e
driver stage and th e power amplifier stage
6
operation
occurs ,
the
3)
detect and
when fault p ower i s
Q-7
in the receiver.
applying
the
ful l battery
It is possible under certain conditions that the
signals from two transmitters, attempting to b i ock a
third receiver, would be of such amplitude, phase and
fre quency
as
to c ause the RRH
"pul sat e " . It would then be possible to have a fal s e
trip.
In the case of the KR set for relaying 3-terminal
lines, the transmitter frequencies ( to avoid thi s pos
sibility of fals e trip) should be separated by 100
cycles. All receivers and one transmitter would b e
for t h e desired center frequency. One of t h e other
transmitters would be 100 cycles above, the other
100 cycles b elow this center frequ ency.
I N S T A L L A T I O N
G e n e r a l
Upon receipt o f a unit , whether shipped separately
or in an assembly, an imm ediate insp ection should be
made. Carefully check for damage or shortag es.
For necessary clearances and mounting dimen
sions, see the following illustrations:
Flexitest Case Mounting . . . . . . . . . . . . . . Fig. 1
S l eet Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . Fig. 1 1
C o n n e c t i on s
External
The external connections will vary slightly de
p ending on the application, but in g eneral will be
along the lines de scribed as follows: ( Refer to the
Schematic Diagram, Fig. 2. )
Terminals 1 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ground
1 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coaxial Cabl e
1 3 and 19 . . . . . . . Supervis ory Preference
14 . . . . . . . . . B- " C ARRIER STOP" return
15 . . . . . . . . . . . . . . . . Battery p ositive through
1 6
. . . . . • . . . . . . . .
17 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-
18 . . . . . . . Carrier stop for H ZM Relaying
1 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B+
20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Relay Coil
C
If the transmitter output load is removed
A UT 10 N
while the transmitter is energized, the transistors in
coil
current
Contacts
carrier st art contacts
B attE:)ry positive for alarm
cutoff ( u sed wit h com
munication)
to
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