Logic Busbar Protection (Lbbp); Figure 79: Logic Scheme Of The Logic Busbar Protection; Figure 80: Single Line Diagram, The Circuit Breaker Is In The Service Position - ABB UniGear Digital Commissioning And Testing Manual

AP PAR ATU S CO NTR O L T E S TI NG
5.2.3

Logic busbar protection (LBBP)

Logic bus bar protection trips selectively the circuit breaker according to the logic scheme.
The start signal of the Overcurrent or Earth fault protection is sent from the Outgoing feed-
ers to the upstream circuit breaker, such as the Incomer, Generator and Bus tie, to block su-
perior Overcurrent or Earth fault protection. For safety reasons, the Logic busbar protection
can only be used with Circuit breaker failure protection.

Figure 79: Logic scheme of the Logic busbar protection

Step 1/10
Move all circuit breaker trucks into the service position in the relative section. Check all the
circuit breakers status on the protection relay LHMIs.

Figure 80: Single line diagram, the circuit breaker is in the service position

1 VLG 500 0 17 C
I NT ER LO C K S BE T W EE N PA NE LS
53