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6 - 53
Siemens AG ⋅ May 1998
6.5.3.3 Check zone
The bus-section specific protection must have a highĆ
er setting than the check zone, so that the check
zone supervision picks up before the bus-section
specific protection.
Example
:
The supervision for the check zone is to be checked
with diff-current limit I > DIFsup : CZ
(DA 6306/ZE) = 0.2 I/I
no.
The time T-DIFF-SUP (DA
6304/ZE) should be set to 2.0 s. The setting for the
bus-section specific protection I > DIFsup : BZ (DA
6305/ZE) could then be 0.8 I/I
no
.
Settings
:
D DIFF.SUPERV set to "active"; DA 6303/ZE
D I > DIFsup:BZ = 0.80 I/I
no
; DA 6305/ZE
D I > DIFsup:CZ = 0.20 I/I
no
; DA 6306/ZE
D T-DIFF-SUP = 2 s; DA 6304/ZE
Test steps
:
a) Checking pick-up limit and time delay
1. The current in feeder 1 is slowly increased until
the supervision of the check zone picks up. The
measured current must correspond to the set curĆ
rent (DA 6306/ZE).
2. Time measurement is performed as in test step 5.
of chapter 6.5.3.2.
b) Checking the blocking
1. When the diff-supervision of the check zone picks
up, the protection can be blocked (DA 6308/ZE)or
an alarm can be issued DIFF SUP CZ = alarm only
2. Bays 1 and 2 are connected to the same bus.
3. The current in feeder 1 is slowly increased until
the supervision of the check zone picks up.
4. In feeder 2, a current of 4 x I
N
is injected. If paĆ
rameter DIFF SUP CZ (DA 6308/ZE) was set to
"block", then no trip commands are issued.
6.5.4 Testing the pick-up values for controlled
tripping
6.5.4.1 Test set-up
(as in chapter 6.5.2.1)
6.5.4.2 Test steps
Settings
:
The overcurrent limit for tripping should be checked
for two feeders "I > TRIP".
Settings
:
D In order to prevent the diff-current supervision
from blocking the protection during testing, it must
be turned off, DIFF SUPERV (DA 6303/ZE).
D The differential current limits for the bus-section
specific protection I>DIFF:BZ (DA 6102/ZE) and
for the check zone I>DIFF:CZ(DA 6104/ZE) are
both set to 1.0 I/I
no
.
D The overcurrent limit for bay 1 (DA 65XX)isset
to 2.0I/I
no
and for bay 2 (DA 65YY)to0.
Test steps
:
1. Bays 1 and 2 are connected to the same busbar
(by simulation of isolator status).
2. The current in bay 1 is slowly increased via the
test set. When reaching approximately 1 x I
N
bay
unit 2 must issue a trip command, because the
overcurrent limit for this bay was set to 0. Bay unit
2 must issue a trip command at 2 x I
N
.
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