14
VII. TRIMPOT ADJUSTMENTS.
The control contains trimpots, which have been factory adjusted for most applications. Figure
1 page 3 illustrates the location of the trimpots and their approximate adjustment positions.
Some applications may require readjustment of the trimpots in order to tailor the control to
exact requirements. (See table 2, p. 5 for range and factory setting of all trimpots.) Readjust
trimpots as follows:
WARNING
. Do
not
adjust trimpots with main power on if possible.
If
adjustments are made with power on, insulated adjustment tools must be used and
safety glasses must be worn. High voltage exists in this control. Electrocution and/or
fire can result if caution is not exercised.
Safety warning must be read and understood
before proceeding
.
A. Minimum Speed (MIN) –
The MIN trimpot is used to set the minimum voltage of the drive.
This sets the minimum speed of the motor. Adjust the MIN trimpot as follows:
1. Rotate Main Potentiometer to minimum speed position (full counterclockwise).
2. Increase setting of MIN trimpot so that motor runs at desired minimum speed.
B. Maximum Speed (MAX) –
The MAX trimpot is used to set the maximum voltage of the
drive. Adjust the MAX trimpot as follows:
1. Rotate Main Potentiometer to maximum speed position (full clockwise).
2. Adjust MAX trimpot setting to desired setting of motor speed.
C. Acceleration (ACCEL) –
The ACCEL trimpot sets the amount of time it takes the control
to reach full output. The trimpot is factory set to one (1) second. If more rapid
acceleration is desired, rotate the trimpot counterclockwise. Note: Rapid ACCEL setting
may cause the current limit circuit to activate which will extend the acceleration time. For
a longer acceleration time, rotate ACCEL trimpot clockwise. 50% rotation represents
approximately seven (7) seconds and full rotation is approximately fifteen (15) seconds.
D. Deceleration (DECEL) –
The DECEL trimpot sets the amount of time it takes the control
to go from full speed to minimum speed when rotating the main potentiometer CCW. The
trimpot is factory set to one (1) second, and can be readjusted to full counterclockwise
position for more rapid DECEL. Note: On high inertial loads, a rapid DECEL setting may
cause the motor to coast to a stop slower than the DECEL setting. To increase
deceleration time, rotate DECEL trimpot clockwise. 50% rotation represents
approximately seven (7) seconds and full rotation is approximately fifteen (15) seconds.
Note: The Decel circuit works when rotating the main speed pot in the CCW direction or
when opening the P3 lead of the main pot or when placing the Start/Stop Switch Toggle
to the Stop position. It does not operate when power is removed.
E. Current Limit (CL) –
This trimpot is used to set the maximum amount of DC current that
the motor can draw. The amount of DC current determines the amount of maximum
motor torque in both the Speed Control Mode and Torque Mode. The CL trimpot is factory
set at 150% of the current established by the jumper J4 selection. Also see section VIII
C, on page 15). Readjust the CL trimpot as follows:
1. Turn CL trimpot to minimum (CCW) position. Be sure jumper J4 is in proper position
approximately equal to the motor DC ampere rating.
2. When jumper J1 is set to the Speed Control Mode the main potentiometer should be
set at 50% rotation. When jumper J1 is set to the Torque Mode the main
potentiometer should be set at 100% of full rotation.
3. Wire in a DC ammeter in series with armature lead. Lock shaft of motor.
4. Apply power. Rotate CL trimpot CW until desired CL setting is reached (factory
setting is 1.5 times rated motor current).
CAUTION:
1. Adjusting the CL above 150% of motor rating can cause overheating and
demagnetization of some PM motors. Consult motor manufacturer.
