5-12 Switch Setting & Start-Up MN792

Power up in Remote Mode with Feedback Continued
8. Reset the MAIN CURR. LIMIT 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 factory setting of 100%). Until this is done, the External Current Clamp will limit the
current to 100%.
a. 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).
b. 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).
c. 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.
Autotune Performance adjustment of the following Current Loop parameters: PROP. Gain, INT. Gain, and 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 motor field is supplied by an external supply, remove the field manually. (If the field is internally
regulated, Autotune automatically quenches the field).
Note: The shaft may require clamping for certain motors to prevent rotation >20% during the Autotune
sequence. If using a permanent magnet motor, the shaft MUST be clamped.
5. Set the AUTOTUNE parameter to ON.
6. Close the main contactor, i.e. Start/Run signal to terminal C3.
7. Enable the control, terminal (C4).
8. The Autotune sequence is initiated. When complete (after approximately 10 seconds), the main
contactor is opened automatically signalling the end of the sequence and the AUTOTUNE parameter
is reset to OFF.
9. Save parameter settings.
10. If necessary, restore field connections and/or remove the mechanical clamp.
If autotune failed – Refer to the Manual Tuning appendix of this manual.
1. The keypad displays the message AUTOTUNE ABORTED.
The Autotune sequence is aborted causing the main contactor to drop out if any of the Initial
Conditions are not present, or if the Autotune sequence times out (after 2 minutes).
2. The Operator Station displays the message AUTOTUNE ERROR.
The Autotune sequence is suspended causing the main contactor to drop out if the motor speed
feedback is greater than 20% of rated speed, or the field current exceeds 6% of rated field current.