Yaskawa Matrix Converter User Manual
Page 345
7
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The voltage tolerance between motor phases is insufficient.
When the motor is connected to the MxC output, a surge is generated between the MxC switching and the
motor coil. Normally the maximum surge voltage is three times the MxC's input power supply voltage (i.e.,
1,200 V for 400 V class). Be sure to use a motor with a voltage tolerance between motor phases that is greater
than the maximum surge voltage. In particular, when using a 400 V class MxC, use a special motor for invert-
ers.
Auto-Tuning has not been performed for Open Loop Vector Control.
Open Loop Vector Control will not operate the motor if Auto-Tuning has not yet been performed. Perform
Auto-Tuning, or calculate and set the motor parameters manually. Alternatively, change the Control Method
Selection to the V/f Control Method (A1-02 = 0).
Noise is Produced from an AM Radio or when the MxC is Started
If noise is generated by MxC switching, then take the following action:
•
Change the MxC's Carrier Frequency Selection (C6-02) to lower the carrier frequency. This will help to
some extent by reducing the amount of internal switching.
•
Install an Input Noise Filter at the MxC's power supply input area.
•
Install an Output Noise Filter at the MxC's power supply output area.
•
Use metal tubing. Electric waves can be shielded by metal, so encase the MxC with metal (steel).
•
Ground the MxC and motor.
•
Separate main circuit wiring from control wiring.
Ground Fault Interrupter Operates while the MxC is Running
The MxC performs internal switching, so there is a certain amount of leakage current. This may cause the
ground fault interrupter to operate and cut off the power supply. Change to a ground fault interrupter with a
high leakage detection level (i.e., a sensitivity current of 200 mA or greater per Unit, with an operating time of
0.1 s or more), or one that incorporates high frequency countermeasures (i.e., one designed for use with
inverter). It will also help to some extent to change the MxC’s Carrier Frequency Selection (C6-02) to lower
the carrier frequency. In addition, remember that the leakage current increases as the cable is lengthened.