Functions
2.12 Direct Local Trip
SIPROTEC, 7SD5, Manual
C53000-G1176-C169-5, Release date 02.2011
285
2.12
Direct Local Trip
Any signal from an external protection or monitoring device can be coupled into the signal processing of the
7SD5 by means of a binary input. This signal can be delayed, alarmed and routed to one or several output
relays.
2.12.1
Functional Description
External trip of the local circuit breaker
Figure 2-145 shows the logic diagram. If device and circuit breaker are capable of single-phase operation, it is
also possible to trip single-pole. The tripping logic of the device ensures that the conditions for single-pole trip-
ping are met (e.g. single-phase tripping permissible, automatic reclosure ready).
The external tripping can be switched on and off with a setting parameter and may be blocked via binary input.
Figure 2-145
Logic diagram of the local external tripping
Remote trip of the circuit breaker at the opposite line end
On conventional transmission paths, one transmission channel per desired transmission direction is required
for remote tripping at the remote end. For example, fibre optic connections or voice frequency modulated high
frequency channels via pilot cables, power line carrier or microwave radio links can be used for this purpose in
the following ways.
If the trip command of the distance protection is to be transmitted, it is best to use the integrated teleprotection
function for the transmission of the signal as this already incorporates the optional extension of the transmitted
signal, as described in Section 2.7. Any of the commands can of course be used to trigger the transmitter to
initiate the send signal.
On the receiver side, the external local trip function is used. The receive signal is routed to a binary input which
is assigned to the logical binary input function
„>DTT Trip L123“
. If single-pole tripping is desired, you can
also use binary inputs
„>DTT Trip L1“
,
„>DTT Trip L2“
and
„>DTT Trip L3“
. Figure 2-145 thus also
applies in this case.
