ABB REB500 - System Blocking Design

1MRK 505 350-UEN Section 2
Signals
Technical Manual 19
Distributed busbar protection REB500
2.6 System blocking design
Certain central and bay unit input signals can directly influence output signals.
Figure 1 shows the blocking system. The numbered items in that figure mean:
1. Default value “1” if the input or function is not configured.
2. The output is blocked when “Block output relays” is active and signal 2) on
HMI500 is configured for blocking.
3. Blocked by isolator or differential current alarm (providing correspondingly
configured via HMI500).
4. Protection function disabled.
5. CTs line side: transfer tripping
CTs busbar side: busbar intertripping
6. Detected automatically by the software when, for example, the CB is bridged.
7. Blocking the bay protection does not block the protection function itself, but
only the logical outputs of the bay protection functions, i.e. although blocked
measurements are still displayed and trips signaled.
8. A BP output signal can be assigned for blocking the BFP function via the
default blocking signal “13210_BP Block BFP”
When signal “31210_Block output relays” is activated, the last
status of all the protection function outputs is retained.
Table 21 and Table 22 list how an input can affect the output signal as explained in
Table 20:
Table 20 Effects of input signals to output signals
Effect Description
B
The signal is not changed
(retained) providing it was configured for blocking.
E
The signal is not changed (retained).
F
Signal enabled (trip interlocked by enabling signal).
K
Blocks providing this blocking function were configured using HMI500.
M
Logic signal
P
Partially
blocked, i.e. the busbar protection does not issue any tripping
commands or signals. Other functions (BFP, EFP), which can also set this
output, are not affected by the blocking signal.
S
The signal is set.
Z
The signal is either reset and blocked or sim
ply blocked if it was not already
blocked when the blocking signal was generated.