ABB RELION REF610, Technical Reference Manual

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At the factory default delay of 300 s for
AR 51P pickup Delay
and
AR 51N pickup Delay
, the pickup signals will, in practise, not be
used for shot initiation. However, if elements 51P or 51N have been
given an IDMT 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 pickup
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 51P pickup Delay
and
AR 51N pickup Delay
for shot initiation and the signal
Open CB Command
has been routed
to the trip output contact, elements 51P and 51N should not be used for
blocking of shot 1.
6.1.3. Selecting adaptive sequence length
The auto-reclose sequence can be set to adapt to the fault current, either through
blocking of shot initiation or disable of the AR function.
In the examples below, three overcurrent elements (51P, 50P-1 and 50P-2) are used
and the number of shots of the AR sequence vary depending on which elements
trips.
Example:
Start by checking that the switches have been properly set:
Settings Function
SG1/1=1 Blocking of initiation of shot 1 by the trip signal from
element 50P-1
SG3/1=1 Disable of the AR function by the trip signal from element
50P-2
Number of shots = 3
If one or several phase currents
*
exceed the set pickup value of element 51P but not of elements 50P-1 and
50P-2, the AR sequence will include shot 1, 2 and 3.
*
exceed the set pickup value of elements 51P and 50P-1 but not of element
50P-2, the AR sequence will include shot 2 and 3.
*
exceed the set pickup value of elements 51P, 50P-1 and 50P-2, no shots
will be performed (AR function disabled).
Feeder Protection Relay
Technical Reference Manual - ANSI Version
REF610 REF610
1MRS755535