Operation Principle; Zone Extension; Loss-Of-Load Acceleration - ABB REL650 Technical Manual

Section 12
Scheme communication
Table 263: ZCLCPSCH Non group settings (basic)
Name
GlobalBaseSel
12.3.6
12.3.6.1
12.3.6.2
448
Values (Range) Unit
1 - 12 -

Operation principle

Zone extension

The overreaching zone is connected to the input EXACC. For this reason,
configure the ARREADY functional input to a READY functional output of a used
autoreclosing function or via the selected binary input to an external autoreclosing
device, see figure 229.
This will allow the overreaching zone to trip instantaneously.
IEC05000157 V1 EN-US
Figure 229: Simplified logic diagram for local acceleration logic
After the autorecloser initiates the close command and remains in the reclaim state,
there will be no ARREADY signal, and the protection will trip normally with step
distance time functions.
In case of a fault on the adjacent line within the overreaching zone range, an
unwanted autoreclosing cycle will occur. The step distance function at the reclosing
attempt will prevent an unwanted retrip when the breaker is reclosed.
On the other hand, at a persistent line fault on line section not covered by
instantaneous zone (normally zone 1) only the first trip will be "instantaneous".
The function will be blocked if the input BLOCK is activated (common with loss-
of-load acceleration).

Loss-of-Load acceleration

When the "acceleration" is controlled by a loss-of-load, the overreaching zone used
for "acceleration" connected to input LLACC is not allowed to trip
"instantaneously" during normal non-fault system conditions. When all three-phase
Step Default
1 1
1MRK 506 382-UEN A
Description
Selection of one of the Global Base
Value groups
Line distance protection REL650 2.2 IEC
Technical manual
M13819-3 v2
M13819-9 v5