AR
Trip CB 3P
ZExtension
C
B
o
p
e
n
C
B
M
a
n
u
a
l
C
lo
se
C
O
r
e
a
d
y
C
lo
s
e
C
B
REB500sys
OR
(Logic)
O/C
O/C
Block
Trip
Trip
I1>, t1
I2>, t2
St art
18000050-IEC19000455-1-en.vsdx
IEC19000455 V1 EN-US
Figure 51: Overcurrent and autoreclosure functions in the same unit
where:
•
t1 standard delay (0.5 ... 1.5 s)
•
t2 short delay (0.02 ... 0.2 s)
•
I
1
>, I
2
> pick-up value
I set for Trip
5.8.6.4
Coordinating autoreclosure (AR) with first and second main protections
GUID-6063E9EF-3D99-4AC7-A11C-4786D0A12FE7 v1
Provision is made for coordinating the operation of the autoreclosure function of main
protection 1 with main protection 2.
To avoid any risk of mal-operation due to differing timer tolerances, precautions are necessary
to ensure that only one autoreclosure function is active per line terminal at any one time.
Main protection 1 (external device) and main protection 2 (REB500sys) are completely
independent protection systems and if each has its own autoreclosure function (
their operation has to be coordinated. As long as the AR function for main protection 1 is in
operation, that of main protection 2 is blocked. To this end, main protection 1 output CO
Ready is connected to input 118205_Ext. Blk AR on the REB500sys bay unit. The starting
signals (Start L1L2L3) and tripping signals (Trip CB and Trip CB 3P) generated by the
REB500sys distance function UZ(2) are connected to their own autoreclosure function AR(2)
and to the autoreclosure function AR(1). The corresponding signals from the external distance
protection UZ(1) are only connected to the external autoreclosure device AR(1). On the other
hand, the signal from AR(1) instructing the distance protection only to perform a three-phase
trip (Trip CB 3P) goes to both distance protection functions UZ(1) and UZ(2). The same signal
from AR(2) only goes to distance protection UZ(2).
The autoreclosure unit AR(1) and the two distance protection functions UZ(1) and UZ(2) are
active in normal operation. An autoreclosure cycle can be initiated by either UZ(1) or UZ(2) as
both communicate with the autoreclosure device AR(1).
Whenever autoreclosure device AR(1) is in the not-ready state, autoreclosure device AR(2) is
activated and communicates with distance protection function UZ(2). AR(1) is generally fitted
in the same bay unit as distance protection UZ(1) and a not ready status applies to both
functions. This means that distance protection and autoreclosure of the line are performed by
main protection 2 (REB500sys).
Section 5
1MRK 505 406-UEN B
Bay protection functions
140
Bay protection functions REB500
Technical manual
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