Mitsubishi Electric A173UHCPU User Manual page 101

3. MOUNTING AND WIRING
Connect input and output wires along different routes.
Leave at least 200 mm (7.87 in) clearance between I/O wires and high-voltage, high-current
main-circuit cables.
If the I/O wires cannot be kept separate from the main-circuit or power cables, use shielded
cable for all of them and ground the shield at the CPU module end. However, if appropriate,
ground the other end of the shield
Keep 24 VDC I/O wires separate from 100 VAC and 200 VAC wires.
The leakage current over long-distance wiring connections exceeding 200 m (656.17 ft.) can lead
to problems.
See Section 5.4.2 (9) for appropriate countermeasures.
Ground resistance to be 100
other equipment.
(c) Keep 24 VDC I/O wires separatlf wires from 100 VAC and 200 VAC wires.
(5) Grounding
Connect the ground wiring as described in steps (a) to (c) below.
(a) Use a separate ground, if possible. Ground resistance 100
3 grounding)
(b) If a separate ground is not possible, connect to ground as shown in (2)
below.
Other
CPU module
equipment
Class 3 grounding
(1) Separate ground connections
.......................... optimum
(c) Grounding cables to be 2 mm
Grounding point to be as close as possible to the
A173UHCPU/A172SHCPUN/A171SHCPUN and the distance to the
grounding point as short as possible.
(6) Module terminal block wiring screws
Tighten the wiring screws of the module terminal block within the following range.
Screw
Terminal block and terminal screws
(M3.5 screws)
CPU module
Input
Output
DC
max (class 3 grounding). Do not share a common ground with
Other
CPU module
equipment
Class 3 grounding
(2) Common ground connection
.......................... acceptable
2
min.
Tightening Torque Range N
CAUTION
Shield cable
Shield
3 − 10
or less. (class
CPU module
(3) Common ground connection
...................... not permitted
59 to 88
RA
Other
equipment
cm