ABB RELION REX640 - Fast transfer - sequential break before make (FBBM)

Busbar
voltage
Main feeder current
Stand-by feeder current
Main feeder breaker (CB1)
Stand-by feeder breaker (CB2)
Main feeder breaker open
command (OPEN_CB1)
Stand
-by feeder close command
(CLOSE_CB2)
1 2 3 4
CB open
delay
CB close
delay
Internal Logic + BO delay
Figure 941: Signal diagram of a fast simultaneous transfer (Fast) (For simplicity
reasons only one voltage is presented in the figure)
1
External fault begins
2 Main feeder breaker open command (OPEN_CB1) and stand-by feeder close
command (CLOSE_CB2), both are HSABTC function outputs
3 Main feeder breaker opens
4 Stand-by feeder breaker closes
If DISA_RUN input is active, transfer is not allowed to complete until input is
deactivated.
When fast transfer is completed, this is indicated with COMPL_FAST output.
Fast transfer – sequential break before make (FBBM)
Fast Sequential break before make transfer is activated if fast transfer has been
enabled with Enable fast transfer (defined in the previous chapter) and Enable
FBBM is “True”. If fast sequential transfer is enabled, then simultaneous transfer is
not enabled, i.e. only one can be active at the same time.
In the sequential fast transfer mode (FBBM) the transfer function waits for the
OPEN position indication of the feeding circuit breaker before issuing the close
command to the circuit breaker of the stand-by feeder. The dead time without
Control functions
1MRS759142 F
1774 REX640
Technical Manual