ABB RELION 620 Series Technical Manual page 356

Section 4
Protection functions
350
and THERMLEV_END outputs respectively. The activation of the BLOCK input does
not have any effect on these outputs.
Alarm and tripping logic
The module generates alarm, restart inhibit and tripping signals.
When the thermal level exceeds the set value of the Alarm thermal value setting, the
ALARM output is activated. Sometimes a condition arises when it becomes necessary
to inhibit the restarting of a motor, for example in case of some extreme starting
condition like long starting time. If the thermal content exceeds the set value of the
Restart thermal val setting, the BLK_RESTART output is activated. The time for the
next possible motor start-up is available through the monitored data view from the
T_ENARESTART output. The T_ENARESTART output estimates the time for the
BLK_RESTART deactivation considering as if the motor is stopped.
When the emergency start signal START_EMERG is set high, the thermal level is set
to a value below the thermal restart inhibit level. This allows at least one motor start-
up, even though the thermal level has exceeded the restart inhibit level.
When the thermal content reaches 100 percent, the OPERATE output is activated. The
OPERATE output is deactivated when the value of the measured current falls below 12
percent of Current reference or the thermal content drops below 100 percent.
The activation of the BLOCK input blocks the ALARM, BLK_RESTART and
OPERATE outputs.
1MRS757644 F
620 series
Technical Manual