Overpressure Flaps Inter-Trip; Figure 87: Logic Scheme Of Ith Limiters Trip; Table 5: Inter-Tripping Rules For Ith Limiters - ABB UniGear Digital Commissioning And Testing Manual

AP PAR ATU S CO NTR O L T E S TI NG
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

Cable compartment of Outgoing feeder
Circuit breaker or Busbar compartment of
Cable or Circuit breaker compartment of Bus
Circuit breaker or Busbar compartment of
Cable or Circuit breaker compartment of In-
Busbar compartment of Incoming feeder
It is assumed that the flaps have been properly set and the connection to the protection relay
has been tested after busbar assembly onsite.
1 VLG 500 0 17 C
Arc location
Outgoing feeder
Tie
Bus Tie
coming feeder
I NT ER LO C K S BE T W EE N PA NE LS
Inter-trip to
-
Incoming feeders and Bus Tie
Incoming feeders
Incoming feeders
Upstream breaker
Bus Tie
57