Overcurrent Definite Time Protection; Mode Of Operation; Configuration Of Overcurrent Protection - ABB RELION REB500 Operation Manual

Section 6
Additional protection options
6.3

Overcurrent definite time protection

6.3.1

Mode of operation

The overcurrent protection (def. time) function operates entirely independently of the other
protection functions in each of the bay units and does not intertrip the respective busbar
protection zone.
1)
IEC18000305 V1 EN-US
Figure 15:
6.3.2

Configuration of overcurrent protection

HMI500 provides the following parameters for setting overcurrent protection.
Parameter
OCDT active
Pick-up value
Delay
All bay and current transformer details are shown in the overview. In the Details view, the
overcurrent protection can be activated per bay and the pick-up setting can be set.
48
setting
I >
L1
I > setting
L2
I > setting
L3
1)
I < setting * RR
L1
1)
I < setting * RR
L2
1)
I < setting * RR
L3
15210_Block OCDT
35220_ Block OCDT (CU)
RR = reset ratio (OCDT)
Typical setting 0.95 when engineering scheme
Block diagram of the overcurrent protection
Min.
0.1
0
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25805_OCDT Start
45805_OCDT Start (CU)
Timer
25105_OCDT TRIP
1
S
OCDT delay 25305_OCDT trip
43305_OCDT trip (CU)
R
&
25405_OCDT blocked
1
OCDT blocked
45405_ OCDT blocked (CU)
12000180-IEC18000305-1-en.vsd
Max. Default
inactive
20.0 2.0
20000 2000
1MRK 505 400-UEN B
GUID-D996EDA5-9B30-4B1D-9C2C-91598EC486E2 v1
GUID-4E675E4F-63B7-4A30-A346-FFB9E9F44FFA v1
Step Unit
0.1 I
N
10 ms
Distributed busbar protection REB500
Technical manual