Current Based Inverse Definite Minimum Time Characteristics - ABB RELION REX640 Technical Manual

Section 11
General function block features
11.2
11.2.1
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Figure 853: Operating effect of the BLOCK input when the selected blocking mode
is "Freeze timer"
If the BLOCK input is activated when the operate timer is running, as described in
Figure 853, the timer is frozen during the time BLOCK remains active. If the timer
input is not active longer than specified by the Reset delay time setting, the operate
timer is reset in the same way as described in
input .
The selected blocking mode is "Freeze timer".
Current based inverse definite minimum time
characteristics
IDMT curves for overcurrent protection
In inverse-time modes, the operation time depends on the momentary value of the
current: the higher the current, the faster the operation time. The operation time
calculation or integration starts immediately when the current exceeds the set Start
value and the START output is activated.
Figure 851, regardless of the BLOCK
1MRS759142 C
REX640
Technical Manual