Assignment To A Protection Zone; Enabling Tripping Commands; Overcurrent Release Of The Trip Command - ABB RELION REB500 Operation Manual

Section 7
Additional functions
7.1.2.2

Assignment to a protection zone

Figure 25
integrated in the hardware of bay unit 2, but VT T5 (2.2) measures the voltage on the busbars
in protection zone I.
The same applies to protection zone II, that is, VT T5 (4.4) is connected at bus-tie breaker 4.1. It
is integrated in the hardware of bay unit 4 but measures the voltage on the busbars in
protection zone II.
7.2

Enabling tripping commands

7.2.1

Overcurrent release of the trip command

It is occasionally specified that when tripping a busbar zone only those feeders are tripped
which are actually conducting fault current (active feeders), while those which are not (passive
feeders) are left connected. This logic can be achieved by configuring an additional low current
check feature per bay unit, which only enables tripping of feeders that are actually conducting
current.
The overcurrent release (low current check feature) is used to enable tripping and intertripping
commands generated by the BBP, BFP and EFP and/or trip redirection (configurable). If the
measured feeder current lies below the pick-up setting of the overcurrent release, tripping of
the particular feeder is prevented.
IEC18000340 V1 EN-US
Figure 26: Principle of the overcurrent release function
Although in the event of a busbar trip and feeder current not exceeding the pick-up of the low
current check feature the feeder concerned is not tripped, a trip event is generated by the
central unit and displayed on its (see
transfer tripping ).
The current pick-up setting can also be used for trip redirection regardless of whether the low
current check feature is configured or not.
Parameter
Overcurrent release active
Pick-up setting when active
The overcurrent release function is processed independently of the release logic.
58
shows that VT T5 (2.2) measures the voltage at bus-tie breaker 2.1. Both are
I I > Pick-up setting
L1 L1
I
I > Pick-up setting
L2 L2
I I > Pick-up setting
L3 L3
BBP TRIP
ITT
BBP TRIP
1
BBP TRIP
Min.
0.1
© Copyright 2019 ABB. All rights reserved
1
&
14000037-IEC18000340-1-en.vsd
REB500 Application Manual , section Intertripping/
Max. Default
inactive
4.0 0.7
1MRK 505 400-UEN B
GUID-90F243AB-6332-46ED-A27D-7AB7C3C78A46 v2
GUID-BA496E1D-CA67-44D6-99C7-080C19B6A86F v1
21110_TRIP
Step Unit
0.1 IN
Distributed busbar protection REB500
Technical manual