Blocking - ABB RED650 Technical Manual

Section 9
Voltage protection
9.1.7.3
238
U1<
ST1
TR1
tReset1
t1
IEC10000040 V3 EN-US
Figure 108: Example for Definite Time Delay stage1 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
1MRK 505 394-UEN A
IEC10000040-3-en.vsd
Line differential protection RED650 2.2 IEC
Technical manual
M15326-20 v8