Mitsubishi Electric MELSERVO EMC, Installation Manuallines

Page: 30 / 44

28
6 EMC COUNTERMEASURES AND EFFECTS
6.1 Reason for grounding the shield on both the cabinet side and servo motor chassis side
6
EMC COUNTERMEASURES AND EFFECTS
6.1
Reason for grounding the shield on both the
cabinet side and servo motor chassis side
For the countermeasure against radiated emissions in inverters and servo amplifiers, multiple point grounding, in which both
ends of the servo motor power cable and encoder cable are grounded, tends to suppress unwanted noise.
Grounding the shielded cable only on the servo amplifier side
The following figure shows only the wiring of the servo motor power cable. Wire the shielded wire of the encoder cable in the
same way as the power cable.
• Example of wiring when the shielded cable is grounded only on the servo amplifier side
• Radiated emissions when the shielded cable is grounded only on the servo amplifier side
The following figure is an example of a measurement result, and does not guarantee the measurement result.
U
V
W
E
Cabinet
To servo
amplifier
Connector
10 cm or less
Shielded cable
Servo motor
When a shielded wire is used
Shield
Connect the shield part or earth wire coming out outside the
cabinet with the earth terminal of the connector at the servo
motor side.
Grounding
Servo motor
Motor
LIMIT: IEC/EN 61800-3 (10 m)
[dBuV/m]
100
100 200 300
Frequency

: Ver. (QP)
 : Hor. (QP)
90
80
70
70
60
50
50
40
30
30
20
10
0
HORIZONTAL/VERTICAL