Mounting and Commissioning
3.3 Commissioning
SIPROTEC, 7SD80, Manual
E50417-G1140-C474-A1, Release date 09.2011
270
Availability of the Protection Data Interfaces
The quality of protection data transmission depends on the availability of the protection data interfaces and the
transmission. Therefore, check the statistic information of the device.
Check the following information:
• Indication no. 7753 „FO A/m“ (availability per minute) and indication no. 7754 „FO A/h“ (availability per
hour) indicate the availability of protection data interface 1. The value of no. 7753 „FO A/m“ should attain
a minimum availability of 99.85% after two minutes of operation. The value of no. 7754 „FO A/h“ should
attain a minimum availability of 99.85% after one hour of operation.
If these values are not attained, the protection communication should be checked.
3.3.7 Tests for Circuit Breaker Failure Protection
General
If the device provides a breaker failure protection and if this is used, the integration of this protection function
in the system must be tested under practical conditions.
Due to the variety of application options and the available system configurations, it is not possible to make a
detailed description of the necessary tests. It is important to observe local conditions and protection and system
drawings.
Before starting the circuit breaker tests it is recommended to isolate the circuit breaker of the tested feeder at
both ends, i.e. line isolators and busbar isolators should be open so that the breaker can be operated without
risk.
Caution!
Also for tests on the local circuit breaker of the feeder a trip command to the surrounding circuit breakers can
be issued for the busbar.
Non–observance of the following measure can result in minor personal injury or property damage.
Therefore, primarily it is recommended to interrupt the tripping commands to the adjacent (busbar) breakers,
e.g. by interrupting the corresponding pickup voltages.
Before the breaker is finally closed for normal operation, the trip command of the feeder protection routed to
the circuit breaker must be disconnected so that the trip command can only be initiated by the breaker failure
protection.
Although the following lists do not claim to be complete, they may also contain points which are to be ignored
in the current application.
Auxiliary Contacts of the CB
The circuit breaker auxiliary contact(s) form an essential part of the breaker failure protection system in case
they have been connected to the device. Make sure the correct assignment has been checked.
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