Advertisement
TOSHIBA
7.3 Repetitive Starting
When the motor is started, the repetitive starting protection checks the
starting current and the starting time to see if the temperature rise exceeds
the rotor':; allowable
the rotor is exceeded, this protective function issues a lock signal to
prevent the motor from starting.
The rotor heating caused by a single starting is expressed by the following
equation:
However, if at starting l(t) = 1st. then the following holds:
Hence, when there is no margin defined in
rise BR(i;) and the allowable rotor temperature rise ~?RM, a lock output is
issued.
temperature
Tst
motor starting time (set) (setting value)
Where Tst:
TSC: allowable rotor locking time (set) (setting value)
1st: starting current (A) (setting value)
If the allowable temperature rise of
rise.
Advertisement
