Section 4 1MDU07212-YN Rev. D
Protection and Control Function
32 REF601 / REJ601 / REM601
Application Manual
The calculation is stopped once motor is in running condition.
In case if speed switch is employed, deactivation of speed switch indicates that the
motor is now rotating and I
2
t protection is blocked.
Cumulative startup protection
This function protects the motor from an excessive number of startups.
When the motor is started, the 1st timer will be started and it resets after the
supervised time tn. When the motor is started next time, the next non-active timer
will start. Function will count the number of active timers at a particular instant. If
the active timers are greater than or equal to set maximum possible setting, it
results into activation of binary output which can be used to block closing
operation (blocking further restart).
If supervised time tn setting is decreased, then the running timer
which are greater than tn will be forced to be equal to new
supervised time tn.
When the function inhibits further restart, it is possible to view the time remaining
for next restart RStr_Ena_t in the measurement view.
When the ESTART RQ emergency start is set high, the cumulative restart inhibit
binary output (i.e. BLK CLOSE) will get blocked as long as the emergency start
signal is active. However the new timer will start as well as the count -down of
other active timers will continue in background.
4.9.2.1 Setting range for startup supervision / stalling protection
Table 18: Setting range for startup supervision/stalling protection I2t n<, 51LRS/14/48/66
Current value for detecting
starting of motor
Disable/Enable the doubling /
blocking of OC-EF protection
Maximum start allowed per
defined supervised time
Supervised time allowed for
maximum starts
1)
Ib rated current of motor defined by base current setting
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