Siemens siprotec 7SD5 User Manual page 512

3 Mounting and Commissioning
The circuit breaker on the protected feeder must be opened, as must be the circuit
breaker at the opposite line end. A fault is again simulated as before. A receive signal
impulse delayed by somewhat more than twice the signal transmission time appears
via the echo function at the opposite line end, and the device issues a trip command.
The circuit breaker at the opposite line end is now closed (while the isolators remain
open). After simulation of the same fault, the receive and trip command appear again.
In this case however, they are additionally delayed by the echo delay time of the
device at the opposite line end (0.04 s presetting, address 2502 Trip/Echo DELAY).
If the response of the echo delay is opposite to the sequence described here, the op-
erating mode of the corresponding binary input (H–active/L–active) at the opposite line
end must be rectified.
The circuit breaker must be opened again.
This test must also be carried out at both line ends, in the case of three terminal lines
at each line end and for each signal transmission path. Finally, please observe the last
margin heading „Important for All Schemes"!
Requirements: Teleprot. E/F is configured in address 132 to one of the compari-
Checking in
son schemes using blocking signal, i.e. BLOCKING. Furthermore, under address 3201
Blocking Scheme
FCT Telep. E/F ON is switched. Naturally, the corresponding send and receive
signals must also be assigned to the corresponding binary output and input.
For more details about the function of the blocking scheme refer to Section 2.9. In the
case of the blocking scheme, communication between the line ends is necessary.
An earth fault in the reverse direction is simulated at the transmitting line end. Subse-
quently, a fault at the receiving end in the direction of the line is simulated. This can be
achieved with a set of secondary injection test equipment at each end of the line. As
long as the transmitting end is transmitting, the receiving end may not generate a trip
signal, unless this results from a higher distance stage. After the simulated fault at the
transmitting line end is switched off, the receiving line end remains blocked for the du-
ration of the transmit prolongation time of the transmitting line end (Send Prolong.,
address 3203). If applicable, the transient blocking time of the receiving line end
(TrBlk BlockTime, address 3210) appears additionally if a finite delay time TrBlk
Wait Time (address 3209) has been set and exceeded.
This test must be performed at both line ends, on a three terminal line at each line end
for each transmission path. However, please finally observe the last margin heading
„Important for All Schemes"!
Important for all If the distance protection was switched off for the signal transmission tests, it may be
Schemes switched on now. If setting parameters were changed for the test (e.g. mode of the
echo function or timers for unambiguous observation of sequences), these must now
be re-set to the prescribed values.
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7SD5 Manual
C53000-G1176-C169-1