Maintenance
291
7SS52 V4 Manual
C53000-G1176-C182-3
If you want to take additional precautionary measures to prevent the protection from
tripping due to an operator mistake, the 7SS52 V4 offers you the following options:
−
Set the operator menu
Control
→
Taggings
→
Set
→
Trip Blocking
on the
central unit to
ON
for as long as test currents are applied. In this operating state
of the protection system, you can check measured values and annunciations
without risk of a spurious trip.
−
You can also set in the operator menu of the central unit
Parameter
→
BU
→
BUXX
the parameter
XX12/CU
) of bay XX to
out of service
- on the bay unit you do the same with the function key
F1
. Check the measured
values and annunciations of the bay unit.
Check the trip circuits of each bay unit with the ancillary function „Circuit breaker
test” (Chapter 6.3.4, page 235).
Check the function of the binary inputs in the bay units and the central unit. To do
so, simulate both states of the binary inputs. The reaction of the protection to the
selected input signal can be analysed via the LED indications or by means of the
contents in the operations or fault event memories.
Check the alarm outputs. The functional check of the alarm relays and of the LEDs
of the central unit is supported by the DIGSI communication software.
−
Check the bay unit outputs. The functional check of the command and alarm
outputs is supported by the local operation and the DIGSI operating program.
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