'(& )( )'& &) ( &!& ")& &$(( $#
Ć
%&( $# #)" &&#$
7 - 1
Siemens AG
⋅
May 1998
The 7SS52 does not require any special maintenance. All circuits processing measured values and
signals are designed in static technique.
As the protection is almost completely self-monitored, from the measuring inputs through the meaĆ
suring systems up to the coils of the trip relays, device faults are automatically annunciated. This
yields an enhanced availability of the protection system. Maintenance tests at short intervals thereĆ
fore become superfluous.
Functional tests of the protection system are recomĆ
mended in intervals of 5 years.
Before executing tests or maintenance works it has
to be ensured that there arises no danger for personĆ
nel and that the tests do not influence station compoĆ
nents which are in service.
The warnings given in chapter 6.5.1 have to be
observed!
1. Check of all measuring circuits with regard to the
accuracy requirements. For this purpose test curĆ
rents have to be injected into each bay unit, their
magnitude lying in the nominal current range (seĆ
lected between 0.8 and 1.2
N
) as well as in the
fault current range (
test
> 6.3
N
). In order to avoid
a protection trip, an external fault has to be simulaĆ
ted.
When testing with fault current, attention has to
be paid to eventual thermal overloading of the inĆ
put current transformers. Currents up to 30 x
N
are permissible for a duration of 10s. After this a
cooling down period should be allowed.
The magnitude of the injected current value is moĆ
nitored by means of reading the bay current at the
master unit (
DA 7800/ZE
). A tolerance of up to 5
% is permissible.
2. Functional test of the trip circuits per bay unit.
They are checked using the integrated supplemenĆ
tary function circuit breaker test (refer to chapters
6.2.5.3 and 6.4.3).
3. Check the function of the binary inputs in the bay
units and the master unit. Both states of the biĆ
nary inputs are simulated. The reaction of the proĆ
tection to the selected input signal can be analyĆ
sed via the LED indications or by means of the
contents in the operations or fault event memoĆ
ries.
4. Check the alarm outputs
Apart from the alarm relay M1 in the bay units the
function of KR5 ("transfer trip") has to be tested.
This can be achieved by
a) simulating the marshalled function or
b) if this causes difficulties, then configuration to
the function circuit breaker test is recommenĆ
ded. Then the function can be started by inteĆ
grated operation.
After completion of the test, the original confiĆ
guration has to be re-established.
The functional check of the alarm relays is supported
by software (refer to chapter 6.2.6.2 "6.Test alarm
relays" on page 6 - 24).
www
. ElectricalPartManuals
. com
Summary of Contents for SIPROTEC 7SS52
Page 1: ... w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 2: ...w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 3: ... Siemens AG 1998 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 6: ... w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 17: ... w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 33: ... w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 34: ... w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 35: ... w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 36: ... w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 44: ... w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 166: ... w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 168: ... w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 170: ... w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 184: ... 1 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 186: ... w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 202: ... 0 0 0 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 206: ... X w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 208: ...w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 209: ...w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 210: ... w w w E l e c t r i c a l P a r t M a n u a l s c o m ...