Operating the Drive 4-17
DC590+ Series DC Digital Drive
Step17: Adjustment for Reversing Drives
For reversing drives, check the maximum reverse speed.
Imbalance in reversing drives can only be corrected by adjusting the ZERO SPD OFFSET parameter, which may be to the
detriment of operation at Zero Setpoint.
Step 18: Re-setting the MAIN CURR. LIMIT parameter
Re-set the MAIN CURR. LIMIT parameter to the original setting that you previously noted in Step 4. If in doubt, set it to
100% to correspond to 100% full load current (FLC).
NOTE The controller cannot achieve 200% current unless the CUR. LIMIT/SCALER parameter is increased to 200% (from
its default setting of 100%). Until this is done, the External Current Clamp will limit the current to 100%, refer to
Appendix D: “Programming” - CURRENT LOOP.
• If the current limit is set higher (maximum 200%) and the motor runs into an overload condition, the current is automatically reduced from the
current limit level down to 103% FLC (continual rating).
• If the motor is overloaded, the controller will reduce the current to 103% of the current calibration. (If the motor continues to rotate it may overheat
and thermal protection should be provided).
• If the motor is overloaded and the current provided by the controller is not enough to maintain rotation, i.e. it stalls, the controller will trip out
showing STALL TRIP alarm, if enabled.
Performance Adjustment
Current Loop - The ARMATURE Autotune Feature
Now perform an Autotune to identify and store the following Current Loop parameters:
PROP. GAIN INT. GAIN DISCONTINUOUS
Initial Conditions
1. Main contactor open, i.e. no Start/Run signal at terminal C3.
2. Set the AUTOTUNE parameter to OFF.
3. Program Stop (terminal B8) and Coast Stop (terminal B9) should be high, i.e. 24V.
4. If the field is being supplied by a third-party controller, remove the field manually. (If the field is internally regulated, Autotune automatically
quenches the field).
IMPORTANT
The shaft may require clamping for certain motors to prevent rotation >20% during the Autotune sequence. If the motor is
either a compound motor (series field), has some residual magnetism, or is a permanent magnet motor it WILL rotate and
the shaft must be clamped. If in any doubt, CLAMP OR BE READY TO STOP THE MOTOR.
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