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APPAR ATUS CO NTRO L TESTING
INTERLOCKS BETWEEN PANELS
1VLG5000 17 C
57
5.2.4
Overpressure flaps inter-trip
The Overpressure relief flaps are fitted with Ith limiters. These send a trip command to the
circuit breaker in case of an electrical Arc inside the switchgear. The trip signal is further dis-
tributed over the switchgear based on the location of the electrical Arc.
It is good practice to also forward the inter-trip to outgoing feeders in the section to inter-
rupt the current contribution from the load like motors.
Figure 87: Logic scheme of Ith limiters trip
Table 5: Inter-tripping rules for Ith limiters
Arc location
Inter-trip to
Cable compartment of Outgoing feeder
-
Circuit breaker or Busbar compartment of
Outgoing feeder
Incoming feeders and Bus Tie
Cable or Circuit breaker compartment of Bus
Tie
Incoming feeders
Circuit breaker or Busbar compartment of
Bus Tie
Incoming feeders
Cable or Circuit breaker compartment of In-
coming feeder
Upstream breaker
Busbar compartment of Incoming feeder
Bus Tie
It is assumed that the flaps have been properly set and the connection to the protection relay
has been tested after busbar assembly onsite.
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