Motor Deceleration Is Too Slow; Vertical-Axis Load Drops When Brakes Are Applied; Motor Burns - Omron SYSDRIVE 3G3HV SERIES User Manual

Operation
H Motor Deceleration Is Too Slow
D Deceleration Time is Too Long Even if Braking Resistor Unit is Connected
• Stall prevention during deceleration is selected with n070.
When the Braking Resistor Unit is connected, always set n070 to 0 (i.e., no stall prevention during
deceleration). If n070 is set to 1, the Braking Resistor Unit will not be used. The parameter n070 is set
to 1 before shipping.
• The deceleration time set with n020 or n022 is too long.
Check the deceleration time setting.
• The motor torque is insufficient.
If the parameter settings are normal and overvoltage does not occur, the motor capacity is insufficient.
The motor capacity should be increased.
H Vertical-axis Load Drops When Brakes are Applied
• The sequence is incorrect.
The Inverter is default-set to remain in DC braking status for 0.5 s after deceleration is complete.
To make sure that the brake holds, use the frequency detection function and apply the brake only when
the detected frequency drops to 3 to 5 Hz or lower. Also at startup, use the frequency detection func-
tion, and release the brake only when the detected frequency is 3 to 5 Hz or higher.
• The DC control current is insufficient.
If the DC control current is insufficient, set a higher DC control current with n064.
• Inappropriate brakes are used.
The holding brake is designed only for holding, not for braking. If the holding brake is used for braking,
the brake pad will wear out much faster than designed. Use an appropriate brake for braking.
H Motor Burns
• The load is excessive.
The motor will burn out if the load is excessive and the effective torque of the motor exceeds the rated
torque of the motor. The motor may have permissible torque for a limited period, such as an eight-hour
rated torque. The motor will burn out if motor is operated with the eight-hour rated torque continuously
for more than eight hours.
Reduce the load or the acceleration and deceleration time of the motor or increase the motor capacity
if the load is excessive.
• The ambient temperature is too high.
The motor will burn out if the motor is operated with its rated torque continuously if the ambient temper-
ature is higher than the permissible ambient temperature of the motor. Always use the motor within the
permissible ambient temperature.
• The dielectric strength of each phase of the motor is insufficient.
Surge occurs between the switching circuit of the Inverter and the coils of the motor if the output of the
Inverter is connected to the motor. Normally, the maximum surge voltage is approximately three times
the power voltage imposed on the Inverter (i.e., 600 V for the 200-V Inverter and 1,200 V for the 400-V
Inverter). Therefore, the dielectric strength of each phase the motor to be used must be higher than the
maximum surge voltage.
Be sure to connect a dedicated motor to the 400-V Inverter.
4-10
Chapter 4