Operating instructions
7SV512
V1
C53000---G1176---C91
100
6.6.2 Testing the circuit breaker failure protection
In order to test the circuit breaker failure protection,
this function must be switched on, i.e. address 1201
BREAK FAIL =
ON
. The end fault protection is made
ineffective by setting address 1220 to T---ENDFAULT
=
1
.
Before a test current is injected, the initiation condi-
tions must be fulfilled: The binary input functions
”
>Start
” (FNo 70, allocated to INPUT 10) and
”
>Trip
” (FNo 72, allocated to INPUT 9 when deliv-
ered) must be energized. Binary input function ”
>B/
F Block
” (FNo 77, allocated to INPUT 8 when deliv-
ered) must not be energized. In addition, input func-
tion ”
>Trip 3pole
” (FNo 73) is energized.
Testing can be performed with single-phase, two-
phase or three-phase test current. When testing
single-phase, the test current is injected via one
phase and earth.
Caution!
!
Test currents larger than 4 times I
N
may
overload and damage the relay if applied
continuously (refer to Section 3.1.1 for
overload capability). Observe a cooling
down period!
For current above 4
¡
I
N
, therefore, measurement
shall be performed dynamically. It should be stated
that the relay picks up at 1.1 times setting value and
does not pick up at 0.9 times setting value. Current
below 4
¡
I
N
can be slowly increased.
When the set value for I---BF (address 1202, factory
setting 0.1 x I
N
) is exceeded the indication ”
BFP
Start
(FNo 473, on LED 1 when delivered) ap-
pears. The further reaction of the breaker failure pro-
tection depends on the parameterized functions.
With two-stage breaker failure protection (address
1203 is set TRIP CRoff =
NO
), the annunciation ”
BFP
CrossTrip
(FNo 506, LED 2 when delivered) ap-
pears after expiry of the time delay T1---3POLE (ad-
dress 1206, 0.00 s when delivered). Check that the
assigned trip relay contacts close (trip relays 3 to 5
when delivered).
After expiry of the time T2---CURRENT (address
1212, factory setting 0.15 s) the annunciation ”
BFP
Trip BB
appears (FNo 507, LED 3 when deliv-
ered). Check that the assigned trip relay contacts
close (trip relays 1 when delivered). Additionally, the
intertrip signal ”
BFP TransTrip
appears (FNo
508, LED 4 when delivered). Check that the as-
signed trip relay contacts close (trip relays 2 when
delivered).
When the delay time T---1---3POLE (address 1206) is
not set to 0.00 s (as delivered), then it must be
noted, that the total delay time until bus-bar trip sig-
nal ”
BFP Trip BB
may be composed of the sum
of T1---3POLE and T2---CURRENT (if address 1211
is set T---TRIP---BB =
T1 + T2
; as delivered), or it is
only the time T2---CURRENT (if address 1211 is set
T---TRIP---BB =
T2
).
With single-stage breaker failure protection (ad-
dress 1203 is set TRIP CRoff =
YES
), address 1211
T---TRIP---BB should be set to
T2
, otherwise address
1206 must be set T1---3POLE must be set to 0.00 s in
order to ensure that this time will not be added to the
expected tripping time. After expiry of T2---CUR-
RENT (address 1212, 0.15 s at delivery) the annun-
ciation ”
BFP Trip BB
appears (FNo 507, LED 3
when delivered). Check that the assigned trip relay
contacts close (trip relays 1 when delivered). Addi-
tionally, the intertrip signal ”
BFP TransTrip
ap-
pears (FNo 508, LED 4 when delivered). Check that
the assigned trip relay contacts close (trip relays 2
when delivered). Switch off the test current.
It must generally be noted that the set times are pure
delay times; operating times of the measurement
functions are not included.
The tests carried out until now have used the current
flow as breaker failure criterion. The following tests
with the breaker auxiliary contact criterion are car-
ried out without test current. The binary inputs as
above remain energized.
In addition, one of the binary input functions for the
breaker auxiliary contacts is energized (FNo 16 to
FNo 20), which is allocated to a binary input (e.g. IN-
PUT 6 for the conditions as delivered), preferably
one that is actually used. Tests can be performed
with single-stage and/or two-stage breaker failure
protection, as it is done with the current tests. But
note that the time delay for the second stage is now
T2---CB---AUX (address 1213).
When the reset time of the protection is measured it
must be considered that the values given in the
Technical data are valid only when the test current is
interrupted at the moment of its zero crossing.
Finally, de-energize all binary inputs.
www
. ElectricalPartManuals
. com