Yaskawa VS-626 MC5 User Manual
Page 255
9.2Troubleshooting
- 11
9.2.3 If the Direction of the Motor Rotation is Reversed
D
The motor output wiring is faulty. When the Inverter T1(U), T2(V), and T3(W) are properly connected
to the motor T1(U), T2(V), and T3(W), the motor operates in a forward direction when a forward run
command is executed. The forward direction depends on the manufacturer and the motor type, so be sure
to check the specifications. Switching two wires among the T1(U), T2(V), and T3(W) will reverse the
direction of rotation.
9.2.4 If the Motor Does Not Put Out Torque or If Acceleration is Slow
J
The torque limit has been reached.
D
When a torque limit has been set in constants L7-01 to L7-04, no torque will be output beyond that limit.
This can cause the torque to be insufficient, or the acceleration time to be too long. Check to be sure that
the value set for the torque limit is suitable.
If the torque limit has been set by multi-function analog inputs H3-05 and H3-09 (set value: 10 to 13),
check to be sure that the analog input value is suitable.
J
The stall prevention level during acceleration is too low.
D
If the value set for L3-02 (stall prevention level during acceleration) is too low, the acceleration time will
be too long. Check to be sure that the set value is suitable.
J
The stall prevention level during running is too low.
D
If the value set for L3-06 (stall prevention level during running) is too low, the speed will drop before
outputting torque. Check to be sure that the set value is suitable.
J
Autotuning not performed during vector control.
D
Vector control is not effective without autotuning. Perform autotuning for motor unit separately.
9.2.5 If the Motor Does Not Operate According to Reference
J
The motor runs faster than reference.
1. The frequency reference bias setting is wrong (the gain setting is wrong).
D
The frequency reference bias set in constant H3-03 is added to the frequency reference. Check to be sure
that the set value is suitable.
2. Frequency bias is set for multi-function analog inputs.
D
When “2” (frequency bias) is set for multi-function analog inputs H3-05 and H3-09, a frequency corre-
sponding to the input voltage (current) is added to the frequency reference. Check to be sure that the set
value and analog input value are suitable.
3. A signal is being input to the frequency reference (current) terminal 14.
D
When “1F” (frequency reference) is set for constant H3-09 (multi-function analog input terminal 14),
a frequency corresponding to the terminal 14 input voltage (current) is added to the frequency reference.
Check to be sure that the set value and analog input value are suitable.
9.2.6 If the Slip Compensation Function Has Low Speed Precision
D
The slip compensation limit has been reached. With the slip compensation function, compensation can-
not be carried out beyond the slip compensation limit set in constant C3-03. Check to be sure that the
set value is suitable.
9.2.7 If There is Low Speed Control Accuracy at High-speed Rotation in Open-loop
Vector Control Mode
D
The motor’s rated voltage is high.
D
The Inverter’s maximum output voltage is determined by its input voltage. (For example, if 200 VAC
is input, then the maximum output voltage will be 200 VAC.) If, as a result of vector control, the output
voltage reference value exceeds the Inverter output voltage maximum value, the speed control accuracy
will decrease. Either use a motor with a low rated voltage (i.e., a special motor for use with vector control)
or change to flux vector control.
9