YASKAWA Varispeed L7, Instruction Manual, Page: 215 / 243

6
-18
‹
If the Motor Does Not Operate Properly
The following causes are possible:
„
The motor does not operate when an external operation signal is input.
The frequency reference is 0.00 Hz or a no speed is selected by the digital inputs. Check the input signals and
the frequency reference settings.
Also make sure to set the Baseblock signal. The inverter does not accept any input if it is base blocked.
„ The load is too heavy
Check the motor current. If it is at the limit of the inverter rated current the load might be too high. Check the
inverter size and the mechanical system. Check also if the brake is operating or not.
‹
If the Direction of the Motor Rotation is Reversed
If the motor rotates in the wrong direction, the motor output wiring may be incorrect. When the Inverter oper-
ates in the forward direction, the forward direction of the motor will depend on the manufacturer and the
motor type, so be sure to check the motor specification
The direction of the motor rotation can be reversed by switching two wires among U, V, and W. If using an
encoder, the polarity will also have to be switchend. If the Inverter is operated in V/f mode also parameter b1-
04 can be used to change the rotation direction.
‹
If the Motor Stalls or Acceleration is Slow
„ The torque limit has been reached.
When a torque limit has been set in parameters L7-01 to L7-04, the output torque will be limited according
these settings. Therefore the motor may not develop enough torque to accelerate or the acceleration time might
be very long.
„ The stall prevention level during acceleration is too low.
If the value set for L3-02 (Stall Prevention Level during Acceleration) is too low, the acceleration time will be
increased. Check that the set value is suitable and that the load is not too large for the motor.
„ The stall prevention level during running is too low.
If the value set for L3-06 (Stall Prevention Level during Running) is too low, the motor speed and torque will
be limited. Check that the set value is suitable and that the load is not too large for the motor.
„ Auto-tuning has not been performed for vector control
Vector control will not work properly if auto-tuning has not been performed. Perform auto-tuning, or set the
motor parameters through calculations.
http://nicontrols.com