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MELSEC-Q
4 INSTALLATION, WIRING AND MAINTENANCE OF THE PRODUCT
[Wiring examples using duct (incorrect example and corrected example)]
Relay
Drive
unit
Drive
unit
Noise source
Relay
Relay
PLC QD
75
Relay Relay
Relay
PLC QD
75
Drive
unit
Drive
unit
Changed
Wiring duct
Wiring duct
Control panel
Control panel
The QD75 and drive units are
placed closely. The connection
cable between the QD75 and
drive units is separately laid
from the power line (in this
example, the cable is outside of
the duct) and is as short as possible.
(power system,
etc.)
Noise source
(power system,
etc.)
The drive units are placed
near the noise source.
The connection cable between
the QD75 and drive units is
too long.
(11) The influence of noise may be reduced by insta lling ferrite cores to the cable
connected to the QD75 as a noise reduction tec hnique.
For the noise reduction techniques related to c onnection with the servo amplifier,
also refer to the instruction manual of the servo amplifier.
(12) If compliance with the EMC directive is not requ ired, the influence of external
noise may be reduced by making the configura tion compliant with the EMC
directive.
For the configuration compliant with the EMC directive, refer to Chapter 3 "EMC
AND LOW-VOLTAGE DIRECTIVES" in the User's Manual (Hardware) of the
used CPU module.