Blocking - ABB Relion 670 Series Technical Reference Manual

1MRK 505 208-UEN B
7.1.2.3
Technical reference manual
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TRIP
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IEC10000040 V1 EN
Figure 108: Example for Definite Time Delay stage operation

Blocking

It is possible to block Two step undervoltage protection UV2PTUV partially or
completely, by binary input signals or by parameter settings, where:
BLOCK:
BLKTR1:
BLKST1:
BLKTR2:
BLKST2:
If the measured voltage level decreases below the setting of IntBlkStVal1, either the
trip output of step 1, or both the trip and the START outputs of step 1, are blocked.
The characteristic of the blocking is set by the IntBlkSel1 parameter. This internal
blocking can also be set to Off resulting in no voltage based blocking.
Corresponding settings and functionality are valid also for step 2.
In case of disconnection of the high voltage component the measured voltage will
get very low. The event will START both the under voltage function and the
blocking function, as seen in figure 109. The delay of the blocking function must
be set less than the time delay of under voltage function.
blocks all outputs
blocks all trip outputs of step 1
blocks all start and trip outputs related to step 1
blocks all trip outputs of step 2
blocks all start and trip outputs related to step 2
Section 7
Voltage protection
IEC10000040-1-en.vsd
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