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TOSHIBA
determined by measuring the motor winding temperature and the ambient
temperature using the RTDs.
The S2E21 receives signals from the three RTDs in the winding at its inputs
the heating time constant and the cooling time constant from the motor
temperature rises. The accuracy of calculating these time constants is
about *10X.
From equation (I). the heating time constant is expressed as
TR = -
From equation (2). the cooling time constant is given by
-
At each start and stop of the motor, the heating time constant and the
cooling time constant are detected over a length of time equivalent to
these time constants.
the heating time constant and the cooling time constant.
[Requirements for detecting the heating time constant]
The olotor is sufficiently cool.
The olotor current--is large enough (not too lightly loaded).
[Requirements for detecting the cooling time constant]
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
-
Five measurements are taken and averaged to determine
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