Power Supply Units
Section 3-4
If the I/O wiring and power cables must be placed in the same duct (for example,
where they are connected to the equipment), shield them from each other using
grounded metal plates. In addition, use shielded cables for the I/O signal lines to
improve noise immunity. Also, connect the shielded cables to the ground ( ) ter
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minal of the PC.
Metal plate (iron)
200 mm min.
1
2
3
Grounding at resistance
of less than 100 W
1 = I/O wiring
2 = General control wiring
3 = Power cables
3-4 Power Supply Units
Use a commercially available 100 to 120-VAC or 200 to 240-VAC power source
to supply power to the AC Power Supply Unit; a 24-VDC power, for the DC Power
Supply Unit. Expansion I/O Racks and Expansion CPU Racks must also be con
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nected to a power source via a Power Supply Unit. If possible, use independent
power sources for the Racks, input devices, and output devices.
Supply power to the CPU Rack and Expansion CPU Rack from the same power
source. If supplied by separate sources or if power is not supplied to the Expan
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sion CPU Rack, the CPU will not operate. It is also recommended that power to
the Expansion I/O Racks be supplied from the same power source as the CPU
and Expansion CPU Racks. In order to supply power to the Expansion I/O Racks
from separate power sources, turn on the power to the Expansion I/O Racks be
-
fore turning on power to the CPU Rack.
Supply power to the various parts of the system (power equipment, controls, PC
system, and DC I/O, etc.) via separate power supplies.
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