Pro-face PL-6930-T41, Руководство пользователя

Страница: 78 / 175

Chapter 4 Installation and Wiring
4-11
4.2.3 Grounding Precaution
This section describes the precautions for grounding the PL unit.
• When supplying power to the PL unit, be sure to
separate the input/output and power lines, as shown.
[diagram (a)]
• If exclusive grounding is not possible, use a common
connection point. [diagram (b)]
4.2.4 I/O Signal Line Placement Precaution
• 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. 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 PL.
When connecting an external
device to the PL 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 of 2mm
2
or greater. Create the
connection point as close to the
PL 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) Common Grounding (OK)
(c)Common Grounding (Not OK)
Other
Equipment
PL Unit
Other
Equipment
PL Unit
Other
Equipment
PL Unit