Mounting and Commissioning
3.3 Commissioning
SIPROTEC, 7SD5, Manual
C53000-G1176-C169-5, Release date 02.2011
563
A simple check of the signal transmission path from one line end is possible via the echo circuit if these release
techniques are used. The echo function must be activated at both line ends, i.e. address
2501
FCT Weak
Infeed
=
ECHO only
; with the setting
ECHO and TRIP
at the remote end of the check a trip command may
result!
An earth fault is simulated in the direction of the line. This may be done with secondary test equipment. As the
device at the opposite line end does not pick up, the echo function comes into effect there, and consequently
a trip command is generated at the line end being tested.
If no trip command appears, the signal transmission path must be checked again, especially also the assign-
ment of the echo signals to the transmit outputs.
This test must be carried out at both line ends, in the case of three terminal lines at each end for each signal
transmission path.
The functioning of the echo delay time and monitoring of the circuit breaker switching status must also be tested
at this time if this has not already been done in the previous section (the operation of the protection at the op-
posite line end is checked):
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 generates 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 contrary to the sequence described here, the operating mode of the corre-
sponding 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“!
Checking in Blocking Scheme
Prerequisites:
Teleprot. E/F
is configured in address
132
to one of the comparison schemes using blocking
signal, i.e
BLOCKING
. Furthermore,
FCT Telep. E/F
is switched
ON
at address
3201
. The corresponding
send and receive signals must 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 reverse direction is simulated at the transmitting line end. Subsequently, 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 equip-
ment 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 duration of the transmit prolongation time of
the transmitting line end (
Send Prolong.
, address
3203
). If applicable, the transient blocking time of the re-
ceiving line end (
TrBlk BlockTime
, address
3210
) is added if a finite delay time
TrBlk Wait Time
(ad-
dress
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“!
