Chapter 6 EMC
- 100 -
•
EMC jumper screw
The AC drive has the built-in safety capacitor groups and VDR group and they are connected by default. If the
leakage current protection switch acts at power-on of the whole machine, remove the EMC jumper screw as
shown in the following gure.
EMC jumper
screw
VDR jumper
screw
6.6 Solutions to Common EMC Interference Problems
The AC drive generates very strong interference. Although EMC measures are taken, the interference may still
exist due to improper cabling or grounding during use. When the AC drive interferes with other devices, adopt the
following solutions.
Interference Type Solution
Current leakage
protection switch
tripping
•
Connect the motor housing to the PE of the AC drive.
•
Connect the PE of the AC drive to the PE of the line voltage.
•
Add a safety capacitor to the power input cable.
•
Add magnetic rings to the input drive cables.
Interference caused
by AC drive during
running
•
Connect the motor housing to the PE of the AC drive.
•
Connect the PE of the AC drive to the PE of the line voltage.
•
Add a safety capacitor to the power input cable.
•
Add a safety capacitor to the interfered signal port or wind the signal cable with magnetic rings.
•
Connect the equipment to the common ground.
Communication
interference
•
Connect the motor housing to the PE of the AC drive.
•
Connect the PE of the AC drive to the PE of the line voltage.
•
Add a safety capacitor to the power input cable.
•
Add a matching resistor between the communication cable source and the load side.
•
Add a common grounding cable to the communication cable.
•
Use a shielded cable as the communication cable and connect the cable shield to the common
grounding point.
I/O interference
•
Increase the capacitance at low-speed DI. A maximum of 0.11 uF capacitance is suggested.
•
Increase the capacitance at AI. A maximum of 0.22 uF capacitance is suggested.