Omron SMARTSTEP A Series User Manual page 160

System Design and Installation
● Three-phase Power Supply Input (R7D-AP08H)
AC power
NFB
Surge absorber
supply
Fuse
2
3.5 mm
Class D ground
(Class 3 ground:
100 Ω or less)
Ground plate
Ground control box
• Ground the motor's frame to the machine ground when the motor is on a movable shaft.
• Use a grounding plate for the frame ground for each Unit, as shown in the above diagrams, and
ground to a single point.
• Use ground lines with a minimum thickness of 3.5 mm
lines are as short as possible.
• If no-fuse breakers are installed at the top and the power supply line is wired from the lower duct,
use metal tubes for wiring and make sure that there is adequate distance between the input lines
and the internal wiring. If input and output lines are wired together, noise resistance will decrease.
• No-fuse breakers, surge absorbers, and noise filters (NF) should be positioned near the input termi-
nal block (ground plate), and I/O lines should be isolated and wired using the shortest distance pos-
sible.
• Insert a fuse for short-circuit failure protection if a surge absorber is installed. As a guideline, select
a fuse with three times the maximum instantaneous current.
• Wire the noise filter as shown at the left in the following illustration. The noise filter should be
installed at the entrance to the control box whenever possible.
Correct: Separate input and output
AC input
1
2
3
Ground
• Use twisted-pair cables for the power supply cables whenever possible, or bind the cables.
3-20
Contactor
Noise filter
X1
NF
1 4
2 5
3 6
E
Controller power supply
AC output
4
NF
5
6
E
R7D-AP@
TB TB
L1 U
L2 V
L3 W
L1C
L2C
CN2
2
2 mm
Thick power line (3.5 mm
2
, and arrange the wiring so that the ground
Wrong: Noise not filtered effectively
AC input
Ground
AC output
Chapter 3
R7M-A@
Metal duct
M
E
2
)
Machine ground
1 4
NF
2 5
3 6
E