Motor Outputs No Torque Or Acceleration Is Slow; Motor Deceleration Is Slow; Motor Burns - Omron VS mini J7 User Manual

Troubleshooting
8-2-4

Motor Outputs No Torque or Acceleration is Slow

The stall prevention level
during running is too low.
The stall prevention level
during acceleration is too
low.
8-2-5

Motor Deceleration is Slow

The deceleration time
setting is too long.
Stall Prevention during
Deceleration
8-2-6

Motor Burns

The load is too big.
The ambient temperature
is too high.
The withstand voltage
between the phases of the
motor is insufficient.
If the value in n57 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.
If the value in n56 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.
Check the deceleration time settings in n17 and n19.
The Inverter incorporates a stall prevention function that will automatically
prolong the period of deceleration if the motor has an excessive amount of
regenerative energy. This function will operate if the period of deceleration
is longer than the set value. If the period of deceleration needs to coincide
with the set value, use an Inverter model with a larger capacity or a model
incorporating a function to process regenerative energy (such as the
VARISPEED V7 or 3G3EV-series Inverter).
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 bun out.
Reduce the load amount by either reducing the load or lengthening the
acceleration/deceleration time. Also consider increasing the motor capa-
city.
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 temperature range.
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 models, and approximately 1,200 V for 400-V models).
Therefore, the dielectric strength of the motor to be used must be higher
than the maximum surge voltage.
Chapter 8-2
125