Dynamatic 15-533-1015, Instruction Sheet, Page: 12 / 14

12
c. When the clutch is being torque limited, decrease the setting of the torque damping
potentiometer r18 CCW until instability (hunting develops. Then increase the setting CW until
stability is attained. Recheck the Torque Limit setting as described in step 11b and readjust if
necessary.
12. Torque Limit PCB 15-444-2 (If normal load cannot be applied)
a. Apply a load to the motor and note the motor current (IR) a load of 50% of full load or more
is desirable.
b. Check the motor nameplate for full load current (IF) of the motor.
c. Connect a voltmeter across terminals 1 and 2 and measure the voltage (VR) at a motor current
of IR
d. Calculate what the voltage would be across terminals 1 and 2 at full load:
VF=
( 𝑉𝑉𝑉𝑉 )×( 𝐼𝐼𝐼𝐼 )
𝐼𝐼𝑉𝑉
VF= Current xfmr output voltage at full load
VR= Current xfmr output voltage at reduced load
IF= Motor current at full load
IR= Motor current at reduced load
e. Disconnect the leads to terminals 1 and 2 on 15-444-2 Modification board and connect a
variac
f. Adjust the variac for VF and adjust the Torque Limit pot until the output speed of the drive
just begins to decrease. Increasing the output of the variac slightly will cause the speed of
the drive to decrease sharply. When making this adjustment DO NOT exceed 75 volts out of
the variac.
g. Torque Limit Damping- Follow the procedure outlined in step 11c. A load must be applied,
and the circuit must be limiting torque to make this adjustment.
13. Jog at Run Speed- Stop the controller, set the Run Speed pot to some slow speed and set the
Run/Jog switch to Jog. Push down the Start pushbutton, the drive will run at the selected slow
speed as long as the Start pushbutton is depressed.