Pulsar TCF-10B, Системное руководство, Страница: 233 / 249

19.1 TTU Description
The optional Trip Test Unit is designed to test
two-frequency or three-frequency transfer trip
units using the TCF–10B. The schematic diagram
of the TTU board (daughter board on the
Transmitter Module) is shown in Figure 19-1.
This board plugs onto the Transmitter board (see
Figure 19-4). The backplane PC board for the
TC/TCF–10B has been modified to bring out the
extra inputs and outputs needed for the TTU
operation. Note, however, that backplanes having
a sub lower than five (5) cannot be used with the
TTU.
The schematic of the backplane is shown in
Figure 7-1. The Timing Diagrams for the TTU are
shown in Figure 19-8 through Figure 19-13.
Jumpers JU6, JU7, JU8, and JU9 provide two
methods of operation:
1) If JU6, JU7, JU8, and JU9 are all in the 2-3
positions, the local transmitter turns off the
GUARD frequency for two (2.0) seconds and
sends one-half (0.5) seconds of TRIP. This
means that the local receiver will be receiving
a “real” TRIP, not a checkback trip.
2) If JU6, JU7, JU8, and JU9 are all in the 1-2
positions, the local transmitter will kill
GUARD and send a checkback TRIP 1 to the
remote. The remote recognizes this and turns
off GUARD to the local and sends a
checkback TRIP 1 to the local receiver. The
local receiver recognizes this and sends a
checkback TRIP 2 to the remote, and the
remote returns a checkback TRIP 2 to the
local receiver. This is used for three-frequency
units.
19.1.1 TTU Cycle
Refer to Figure 19-1 and the Timing Diagrams
(Figure 19-8 through Figure 19-13) for the
following sequence of events describing a TTU
cycle. Both the local substation (LS) and the
remote substation (RS) are sending GUARD
(HIGH) frequency.
19.1.2 Local Substation Transmitter
You initiate a test sequence either by pressing S1
(TT INITIATE) on the front panel or by applying
the appropriate voltage to terminals 6 and 7 of
TB4 on the backplane. This causes U12 pin 5 to
go LOW and initiates the 0/7.0- or 0/3.0-second
TTU interval (U9.1 pin 6-TP4). Combining the
TT INITIATE and the unkey line P1-17 causes the
transmitter to be unkeyed for an interval of two (2)
seconds (U9.2 pin 10-TP5). At the end of the two-
second “UNKEY” interval, a half-second
(0.5-second) or two-second (2.0-second) SHIFT
LOW command is generated on TP7. Jumper JU8
in positions 1 to 2 generates a half-second (0.5-
second) of TRIP; JU8 in positions 2 to 3 generates
two seconds (2.0 seconds) of TRIP.
Copyright © 1997 Pulsar Technologies, Inc.
Chapter 19. Optional Trip Test Unit (TTU)
19
Schematic 1614C25-3
Parts List 1614C27-4