Selecting Adaptive Sequence Length - ABB REF 610 Technical Reference Manual

1MRS755310
6.1.3.
Feeder Protection Relay
Technical Reference Manual
At the factory default delay of 300 s for AR I> start Delay and AR
> start Delay, the start signals will, in practise, not be used for
I
0
shot initiation. However, if stages I> or I
characteristic, the factory default delay of 300 s will function as a trip
time limiter. With small currents, the operate time at IDMT
characteristic may be relatively long. However, since the start signals
are always routed to the AR function, the circuit breaker will be tripped
and a shot initiated (provided that the signal Open CB Command has
been routed to the trip output contact) on expiration of the factory
default delay.
When using AR I> start Delay and AR I
shot initiation and the signal Open CB Command has been routed to
the trip output contact, stages I> and I
blocking of shot 1.

Selecting adaptive sequence length

The auto-reclose sequence can be set to adapt to the fault current, either through
blocking of shot initiation or inhibition of the AR function.
In the examples below, three overcurrent stages (I>, I>> and I>>>) are used and the
number of shots of the AR sequence vary depending on which stages trips.
Example:
Start by checking that the switches have been properly set:
Settings
SG1/1=1
SG3/1=1
Number of shots = 3
If one or several phase currents
exceed the set start value of stage I> but not of stages I> and I>>, the AR
*
sequence will include shot 1, 2 and 3.
exceed the set start value of stages I> and I>> but not of stage I>>>, the
*
AR sequence will include shot 2 and 3.
exceed the set start value of stages I>, I>> and I>>>, no shots will be
*
performed (AR function inhibited).
Stage I>>> should have the shortest and stage I> the longest
operate time.
> have been given an IDMT
0
> should not be used for
0
Function
Blocking of initiation of shot 1 by the trip signal from
stage I>>
Inhibition of the AR function by the trip signal from stage
I>>>
REF 610 REF 610
> start Delay for
0
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