Yaskawa Matrix Converter User Manual

Page 49

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Wiring Main Circuit Terminals

2-

15

Preventing Inductive Noise

As described previously, a noise filter can be used to prevent inductive noise from being generated on the out-
put side. Alternatively, cables can be routed through a grounded metal pipe to prevent inductive noise. Keep-
ing the metal pipe at least 30 cm away from the signal line considerably reduces inductive noise.

Fig 2.13 Countermeasures Against Inductive Noise

Counteracting RMS

Radio noise is generated from the MxC as well as from the input and output lines. To reduce radio noise,
install noise filters on both input and output sides, and also install the MxC in a totally enclosed steel box.

The cable between the MxC and the motor should be as short as possible.

Fig 2.14 Countermeasures Against Radio Interference

Cable Length between the MxC and Motor

If the cable between the MxC and the motor is comparatively long, the high-frequency leakage current will
increase, causing the MxC output current to increase as well. This may affect peripheral devices. To prevent
this, adjust the carrier frequency (set in C6-01, C6-02) as shown in Table 2.5 (for details, refer to Chapter 5
Parameters and Settings
).

Table 2.5 Cable Length between MxC and Motor

Cable length

50 m max

100 m max

More than 100 m

Carrier frequency

12 kHz max

8 kHz max

4 kHz max

IM

Power
supply

MxC

Signal line

Controller

Metal pipe

30 cm min.

IM

MCCB

Power
supply

Metal pipe

Noise
filter

Steel box

MxC

Noise
filter

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