Proface APL3000B - Node Box PC - Manual (Page 96)

Chapter 3 Installation and Wiring
3-29
3.3.3 Grounding
This section describes the precautions for grounding the PS-A unit.
• When supplying power to the PS-A unit, be sure to separate the
input/output and power lines, as shown. [diagram (a)]
• If exclusive grounding is not possible, use a common
grounding point. [diagram (b)] A grounding or equivalent
should be used for the grounding point.
3.3.4 I/O Signal Line Placement
• Input and output signal lines must be separated from the power control cables for operating circuits.
• If this is not possible, use a shielded cable and ground the edge of the shield.
Do not use common grounding, since it can lead to an accident or machine breakdown.
• Check that the grounding resistance is
100
Ω or less.
• FG and SG terminals are internally
connected in the PS-A. When
connecting an external device to the
PS-A using the SG terminal, be sure to
check that no short-circuit loop is
created when you setup the system.
• The grounding wire should have a cross
sectional area greater than 2mm
2
Create the grounding point as close to
the PS-A unit as possible, and make
the wire as short, as possible. When
using a long grounding wire, replace the
thin wire with a thicker wire, and place it
in a duct.
• If the equipment does not function properly
when grounded, disconnect the ground wire
from the FG terminal.
(a) Exclusive Grounding (BEST)
(b) Exclusive Grounding (OK)
(C) Common Grounding (Not OK)
PS-A
PS-A
PS-A
Other
Equipment
Other
Equipment
Other
Equipment