Power Supply Circuit Design - Mitsubishi Electric Melsec-Q172DCPU User Manual

3 DESIGN

3.2.1 Power supply circuit design

This section describes the protective coordination and noise suppression techniques of
the power supply circuit.
(1) Separation and protective coordination (leakage current protection,
over current protection) of power supply lines
Separate the lines for Multiple CPU system power supplies from the lines for I/O
devices and servo amplifiers as shown below.
When there is much noise, connect an insulation transformer.
Main power
supply
100/200VAC
100/200/400VAC
(2) Grounding
The Motion system may malfunction as it is affected by various noises such as
electric path noises from the power supply lines, radiated and induced noises
from other equipment, servo amplifiers and their cables, and electromagnetic
noises from contactors. To avoid such troubles, connect the earthing ground of
each equipment and the shield grounds of the shielded cables to the earth.
For grounding, use the exclusive ground terminal wire of each equipment or a
single-point earth method to avoid grounding by common wiring, where possible,
since noises may sneak from other equipment due to common impedances.
100/200VAC
(Note): Be sure to ground the line noise filter, Multiple CPU system, servo amplifier and
servo motor. (Ground resistance: 100
PLC power
supply
MCCB CP
I/O power supply
CP
Motor power supply
CP
Main circuit power supply
for servo amplifier
MCCB
Control power supply
for servo amplifier
CP
Line noise Multiple CPU
filter system
SSCNET
Servo amplifier
3 - 8
Isolation
transformer
Multiple CPU
system
T1
I/O equipment
Motor equipment
Servo amplifier
(/H)
Servo
motor
or less )