Motor Burns; Controller Or Am Radio Receives Noise When Inverter Is Started; Ground Fault Interrupter Is Actuated When Inverter Is Started - Omron SYSDRIVE 3G3MV SERIES User Manual

Maintenance Operations

8-2-8 Motor Burns

• The load is too big.
If the load of the motor is too big and the motor is used with the effective torque exceeding the rated
torque of the motor, the motor will burn out. For example, the rated torque of the motor and capacity
may be limited to eight hours of use if the inscription on the motor states that the motor is rated for
eight hours. If the 8-hour rated torque is used for normal operation, it may cause the motor to burn
out.
Reduce the load amount by either reducing the load or lengthening the acceleration/deceleration
time. Also consider increasing the motor capacity.
• The ambient temperature is too high.
The rating of the motor is determined within a particular ambient operating temperature range. The
motor will burn out if it runs continuously at the rated torque in an environment in which the maximum
ambient operating temperature is exceeded.
Lower the ambient temperature of the motor to within the acceptable ambient operating tempera-
ture range.
• The withstand voltage between the phases of the motor is insufficient.
When the motor is connected to the output of the Inverter, a surge will be generated between the
switching of the Inverter and the coil of the motor.
Normally, the maximum surge voltage is approximately three times the input power supply voltage
of the Inverter (i.e., approximately 600 V for 200-V Inverters, 1,200 V for 400-V Inverters).
Therefore, the dielectric strength of the motor to be used must be higher than the maximum surge
voltage.
In particular, use a dedicated motor for 400-V Inverters.
8-2-9 Controller or AM Radio Receives Noise when Inverter is
Started
• Noise derives from Inverter switching.
Take the following actions to prevent noise.
S Lower the carrier frequency of the Inverter in n080.
The number of internal switching times is reduced, so noise can be reduced to some extent.
S Install an Input Noise Filter.
Install an Input Noise Filter on the power input area of the Inverter.
S Install an Output Noise Filter.
Install an Output Noise Filter on the output area of the Inverter.
S Use metal tubing.
Electric waves can be shielded by metal. Therefore, enclose the Inverter with a metal tube.
8-2-10 Ground Fault Interrupter is Actuated when Inverter is
Started
• Leakage current flows through the Inverter.
The Inverter performs internal switching. Therefore, a leakage current flows through the Inverter.
This leakage current may actuate the ground fault interrupter, shutting the power OFF.
8-18
Chapter 8