1-58
Table 1-4.Shorted Stator
SYMPTOMS
TROUBLE
SETTING OR
CONDITIONS
INDICATION
When TX is on 120º or 300º
but
When TX is between 340º and
80º , or between 160º and 260º
Overload Indicator goes out and TR
reads correctly
Overload Indicator lights, units get hot
and hum, and TR stays on 120º or 300º,
or may swing suddenly from one point
to the other.
Stator circuit shorted
from S1 to S2
When TX is on 60 º or 240º
but
When TX is between 280º and
20º, or between 100º and 200º
Overload Indicator goes out and TR
reads correctly
Overload Indicator lights, units get hot
and hum, and TR stays on 60º or 240º
or may swing suddenly from one point
to the other
Stator circuit shorted
from S2 to S3Stator
circuit shorted from S2
to S3
When TX is on 0º or 180º
but
When TX is between 40º and
140º , or between 220º and
320º
Overload Indicator goes out and TR
reads correctly
Overload Indicator lights, units get hot
and hum, and TR stays on 0º or 180º,
or may swing suddenly from one point
to the other
Stator circuit shorted
from S1 to S3 Stator
circuit shorted from S1
to S3
Table 1-5.Open Stator
SETTINGS OR
CONDITIONS
INDICATION
TROUBLE
When TX is on 150º or 330º
and
When TX is held on 0º
TR reverses or stalls and Overload
Indicator lights TR moves between
300º and 0º in a jerky or erratic
manner
S1 stator circuit open
When TX is on 90º or 270º
and
When TX is held on 0º
TR reverses or stalls and Overload
Indicator lights TR moves to 0º or 180º
, with fairly normal torque
S2 Stator circuit open
When TX is on 30º or 210º
and
When TX is held on 0º
TR reverses or stalls and Overload
Indicator lights TR moves between 0º
and 60º in a jerky or erratic manner
S3 stator circuit open
When TX is set at 0°, and then
moved smoothly
counterclockwise