Table of Contents
Advertisement
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
Cabinet
Grounding
10 cm or less
To servo
amplifier
When a shielded wire is used
• 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.
LIMIT: IEC/EN 61800-3 (10 m)
[dBuV/m]
100
90
80
70
60
50
40
30
20
10
0
30
6 EMC COUNTERMEASURES AND EFFECTS
28
6.1 Reason for grounding the shield on both the cabinet side and servo motor chassis side
Connector
Connect the shield part or earth wire coming out outside the
cabinet with the earth terminal of the connector at the servo
motor side.
Servo motor
Shielded cable
50
70
Servo motor
U
Motor
V
W
E
Shield
100
: Ver. (QP)
: Hor. (QP)
HORIZONTAL/VERTICAL
200
300
Frequency
Advertisement
Table of Contents
