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Application Precautions 5
• Always use the power supply voltages specified in the operation manuals.
An incorrect voltage may result in malfunction or burning.
• Take appropriate measures to ensure that the specified power with the
rated voltage and frequency is supplied. Be particularly careful in places
where the power supply is unstable. An incorrect power supply may result
in malfunction.
• Install external breakers and take other safety measures against short-cir-
cuiting in external wiring. Insufficient safety measures
• Make sure that all the Backplane mounting screws, terminal block screws,
and cable connector screws are tightened to the torque specified in the
relevant manuals. Incorrect tightening torque may result in malfunction.
• Leave the label attached to the Unit when wiring. Removing the label may
result in malfunction if foreign matter enters the Unit.
• Remove the label after the completion of wiring to ensure proper heat dis-
sipation. Leaving the label attached may result in malfunction.
• Use crimp terminals for wiring. Do not connect bare stranded wires
directly to terminals. Connection of bare stranded wires may result in
burning.
• Observe the following precautions when wiring the communications
cable.
• Separate the communications cables from the power lines or high-ten-
sion lines.
• Do not bend the communications cables past their natural bending ra-
dius.
• Do not pull on the communications cables.
• Do not place heavy objects on top of the communications cables.
• Always lay communications cable inside ducts.
• Use appropriate communications cables.
• Make sure that the terminal blocks, expansion cable connectors, and
other items with locking devices are locked in place.
• Wire all connections correctly according to instructions in this manual.
• Double-check all wiring and switch settings before turning ON the power
supply. Incorrect wiring may result in burning.
• Mount Units only after checking terminal blocks and connectors com-
pletely.
• Check the user program for proper execution before actually running it on
the Unit. Not checking the program may result in unexpected operation.
• Confirm that no adverse effect will occur in the system before attempting
any of the following. Not doing so may result in an unexpected operation.
• Changing the operating mode of the PLC.
• Force-setting/force-resetting any bit in memory.
• Changing the present value of any word or any set value in memory.
• After replacing Units, resume operation only after transferring to the new
CPU Unit and/or Special I/O Units the contents of the DM Area, HR Area,
programs, parameters, and other data required for resuming operation.
Not doing so may result in an unexpected operation.
• Before touching a Unit, be sure to first touch a grounded metallic object in
order to discharge any static build-up. Not doing so may result in malfunc-
tion or damage.