ABB REF615 Applications Manual page 67

1MRS756378 D
REF615
Application Manual
A071348 V3 EN
Figure 25: Overcurrent protection
Four overcurrent stages are offered for overcurrent and short-circuit protection. The
instantaneous stage (PHIPTOC1) can be blocked by energizing the binary input 1
(X120:1-2). Two negative sequence overcurrent stages (NPSTOC1 and NPSTOC2)
are offered for phase unbalance protection. The inrush detection block's
(INRPHAR1) output BLK2H caters the possibility to either block the function or
multiply the active settings for any of the shown protection function blocks.
All operate signals are connected to the Master Trip and also to the alarm LEDs. LED
1 is used for overcurrent and LED 4 for negative sequence overcurrent protection
operate indication. LED 4 is also used for phase discontinuity protection operate
indication.
There are four IED variant specific setting groups. Parameters can be set
independently for each setting group.
The active setting group (1...4) can be changed with a parameter. The change of an
active setting group can also be made via a binary input if the binary input is enabled
Section 3
REF615 variants
61