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REF 610
5.1.3.
140
Feeder Protection Relay
Technical Reference Manual
Note!
When using AR I> Start Delay and AR Io> Start Delay for shot
initiation and the signal Open CB Command has been routed to the trip output
contact, stages I> and I
0
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 1
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 stage I>>
SG3/1=1
Inhibition of the AR function by the trip signal from stage I>>>
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).
Note!
Stage I>>> should have the shortest and stage I> the longest operate time.
Example 2
Start by checking that the switches have been properly set:
Settings
Function
SG1/5=1
Blocking of initiation of shot 2 and 3 by the trip signal from stage I>>
SG3/1=1
Inhibition of the AR function by the trip signal from stage I>>>
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 includes only shot 1
• exceed the set start value of stages I>, I>> and I>>>, no shots will be performed
(AR function inhibited).
Note!
Stage I>>> should have the shortest and stage I> the longest operate time.
> should not be used for blocking of shot 1.
1MRS 755310
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