B&C Technologies DI-475 Industrial - Manual (Page 37)

3. Adjustments for reduced voltage soft controllers
This procedure to be used with ALL Series 154-A11NB OR 21B OR 25 control styles.
To properly adjust a soft start controller to give a satisfactory start, two characteristics
Of the motor and load must be considered. The frictional load determines the amount
Of torque required to break-away or obtain initial movement of the motor and load. A
System with a high frictional load will require a higher setting of the START TORQUE
Adjustment than a system with little or no frictional load. Second, the amount of inertia
In the system will determine the START TIME adjustment setting. Generally, systems
With low inertia will require a long START TIME adjustment to give a satisfactory start,
Whereas, systems with inertia may need only a very short START TIME . The softest
Possible start will occur when the start time adjustment is set to maximum and the
Initial torque adjustment is set at the point where the motor just starts the tumbler
Moving when power is first applied.
a. START TORQUE Adjustment
The START TORQUE adjustment is factory preset for maximum torque (maximum
Starting voltage).
1) Rotate the START TIME adjustment fully clockwise so that the longest starting
Time is obtained.
2) Rotate the START TORQUE adjustment to midrange on the dial which will lower
The starting torque.
3) Start the motor. If more or less torque is desired, turn off the power, and rotate
The START TORQUE adjustment in the appropriate direction until an acceptable
Soft start is obtained.
b. START TIME Adjustment
The START TIME adjustment range is ½ to 30 seconds. The higher the valve of
The START TORQUE, the shorter the duration of the overall time period.
1) During the START TORQUE, adjustment process, the START TIME was
Adjusted for the longest start possible. If a shorter time is required, rotate the
Adjustment counterclockwise.
2) Start the motor and determine if the soft start is acceptable.
a) If not, continue to rotate the START TIME adjustment until an acceptable
Start is obtained.