Siemens 7SJ85 - Settings

In an arc-suppression-coil-ground system in feeders with a very large reactive current, it can be practical to set
a somewhat larger angle α1 to avoid a false pickup based on transformer and algorithm tolerances.
Parameter: V0> threshold value
•
Default setting (_:103) V0> threshold value = 30.000 V
The V0> threshold value parameter allows you to set the zero-sequence voltage sensitivity of the stage.
The threshold value must be smaller than the minimum amount of the zero-sequence voltage V0 which must
still be detected.
Parameter: Dir. determination delay
•
Default setting (_:104) Dir. determination delay = 0.10 s
The start of the ground fault normally indicates a significant transient behavior. This can lead to an incorrect
direction decision. The direction determination can be delayed for this reason from the occurrence of the zero-
sequence voltage with the Dir. determination delay parameter to achieve steady-state measurands.
The duration of the transient cycle is determined from the system conditions and the respective fault charac-
teristics. If you have no knowledge of a suitable time delay, Siemens recommends keeping the default setting.
Parameter: Operate delay
•
Default setting (_:6) Operate delay = 2.0 s
The Operate delay parameter determines the time during which the pickup conditions must be met to
issue the operate indication. The operate indication is issued when this time expires.
Settings
Addr.
Parameter C Setting Options Default Setting
Y0> G0/B0 #
_:1 Y0> G0/B0 #:Mode
•
off
•
on
•
test
off
_:2 Y0> G0/B0 #:Operate &
flt.rec. blocked
•
no
•
yes
no
_:10 Y0> G0/B0 #:Blk. by
meas.-volt. failure
•
no
•
yes
yes
_:27 Y0> G0/B0 #:Blk. w.
inrush curr. detect.
•
no
•
yes
no
_:110 Y0> G0/B0 #:Blk. after
fault extinction
•
no
•
yes
yes
_:108 Y0> G0/B0 #:Directional
mode
•
forward
•
reverse
forward
_:109 Y0> G0/B0 #:Dir. meas-
uring method
•
G0
•
B0
G0
_:107 Y0> G0/B0 #:φ correc-
tion
-45 ° to 45 ° 0 °
_:102 Y0> G0/B0 #:Polarized
G0/B0 threshold
0.10 mS to 100.00 mS 2.00 mS
_:105 Y0> G0/B0 #:α1 reduc-
tion dir. area
1 ° to 15 ° 2 °
_:106 Y0> G0/B0 #:α2 reduc-
tion dir. area
1 ° to 15 ° 2 °
6.15.8.3
Protection and Automation Functions
6.15 Sensitive Ground-Fault Detection
SIPROTEC 5, Overcurrent Protection, Manual 599
C53000-G5040-C017-8, Edition 07.2017