ABB eVM1 Installation And Service Instructions Manual page 89

14.7.3.5.3 Thermal memory
To prevent machine overheating in the case of intermittent negative phase sequence current, the
internal time counter is not cleared when the negative phase sequence current falls below the
start threshold. Instead, it is linearly decremented with time, using a user-configurable slope (i.e.
Time Decreasing Rate). 100% means full memory, 0% means no memory.
14.7.3.5.4 NPS function State Machine
Initial Status → → → → → Final Status
Transition #
PASSIVE → → → → → PASSIVE
[1]
PASSIVE → → → → → START
[2]
START → → → → → PASSIVE
[3]
START → → → → → START
[4]
START → → → → → TRIP
[5]
TRIP → → → → → TRIP
[6]
TRIP → → → → → BLOCK
[7]
BLOCK → → → → → BLOCK
[8]
BLOCK → → → → → PASSIVE
[9]
TRIP → → → → → PASSIVE
[10]
Condition(s)
OR Reset_signal_received
AND
AND t ≥
t
TRIP
OR Reset_signal_received
Reset_signal_received
Fig. 75
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