E6580757
Extremely low loads and low inertia loads
The motor may demonstrate instability such as abnormal vibrations or overcurrent trips at light loads of 50 percent or under of the load percentage, or when the load's inertia moment is extremely small. If that happens reduce the carrier frequency.
Occurrence of instability
Unstable phenomena may occur under the load and motor combinations shown below. | 1 |
Combined with a motor that exceeds applicable motor ratings recommended for the inverter | |
Combined with special motors such as |
To deal with the above lower the settings of inverter carrier frequency. (Do not set to 2.2kHz or lower during vector control).
Combined with couplings between load devices and motors with high backlash
In this case, set the
Combined with loads that have sharp fluctuations in rotation such as piston movements
In this case, adjust the response time (inertial moment setting) during vector control or switch to V/f control.
Braking a motor when cutting off power supply
A motor with its power cut off goes into
Loads that generate negative torque
When combined with loads that generate negative torque the protection for overvoltage and overcurrent on the inverter will go into operation and may cause a trip. For this kind of situation, you must install a dynamic braking resistor, etc. that complies with the load conditions.
Motor with brake
If a motor with brake is connected directly to the output side of the inverter, the brake will not release because voltage at startup is low. Wire the brake circuit separately from the motor's main circuits.
MC2
MC1 |
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FLB FLC ST | CC | |
power supply |
| MC3 |
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| |
MC1 |
| MC3 |
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| |
MC3 |
| MC2 |
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B
IM
MC1
MC2
B
IM
RY RC
MC2
Circuit Configuration 1Circuit Configuration 2
In circuit configuration 1, the brake is turned on and off through MC2 and MC3. If the circuit is config-
