Motor Rotates In The Wrong Direction; Motor Outputs No Torque Or Acceleration Is Slow - Omron SYSDRIVE 3G3MV SERIES User Manual

Maintenance Operations
• The auxiliary frequency reference and frequency gain are not input by the multi-function analog in-
puts.
If frequency reference 2 is selected when an auxiliary frequency reference is set for a multi-function
analog input, the analog value of the multi-function analog input will become the frequency refer-
ence. Also, if the frequency gain is set, the specified frequency will be multiplied by a factor propor-
tional to the analog value of the multi-function input. In either case, if no analog voltage is input by the
multi-function analog input, the Inverter will not operate. Check the multi-function analog input ter-
minal parameters (n077, n078) and the wiring.
H The motor stops during acceleration or when a load is connected.
• The load may be too big.
The 3G3MV has a stall prevention function and automatic torque boost function, but the motor
responsiveness limit may be exceeded if acceleration is too rapid or if the load is too big.
Lengthen the acceleration time or reduce the load. Also consider increasing the motor capacity.
H The motor only rotates in one direction.
• Reverse rotation-prohibit is selected.
If n006 for reverse rotation-prohibit selection is set to 1 (reverse run prohibited), the Inverter will not
accept reverse-rotation commands.
To use both forward and reverse rotation, set n05 to 0.

8-2-3 Motor Rotates in the Wrong Direction

• The output wiring of the motor is faulty.
When the U, V, and W terminals of the Inverter are properly connected to the U, V and W terminals of
the motor, the motor will operate in a forward direction when a forward rotation command is
executed. The forward direction depends on the manufacturer and the motor type. Therefore, be
sure to check the specifications.
Switching two wires among the U, V, and W will reverse the direction of rotation.

8-2-4 Motor Outputs No Torque or Acceleration is Slow

• The Inverter in vector control is restricted by the torque compensation limit.
If the torque compensation limit in n109 is set to a value that is too small, the motor torque will be
limited to a low value and sufficient torque will not be available.
If no torque restriction is required, set the parameter to a range from 150% (default setting) to 200%.
• The stall prevention level during operation is too low.
If the value in n094 for stall prevention level during operation is too low, the speed will drop before
torque output is turned ON.
Check to be sure that the set value is suitable.
• The stall prevention level during acceleration is too low.
If the value in n093 for stall prevention level during acceleration is too slow, the acceleration time will
be too long.
Check to be sure that the set value is suitable.
8-16
Chapter 8