Omron trajexia CJ1W-MCH72 Operation Manual page 9

Application precautions
!Caution
!Caution
!Caution
!Caution
!Caution
!Caution
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• Fail-safe measures must be taken by the customer to ensure safety in the event of
incorrect, missing, or abnormal signals caused by broken signal lines, momentary
power interruptions, or other causes.
• Interlock circuits, limit circuits, and similar safety measures in external circuits (i.e.,
not in the Programmable Controller) must be provided by the customer.
• Install external breakers and take other safety measures against short-circuiting in
external wiring. Insufficient safety measures against short-circuiting may result in
burning.
• Install the PLC Unit as far as possible from sources of strong harmonic noise.
• Lock the sliders securely until they click into place when connecting the Power
Supply Unit, CPU Unit, I/O Units, Special I/O Units, or CPU Bus Units. Functions
may not work correctly if the sliders are not locked properly.
• Always attach the End Cover provided with the CPU Unit to the Unit on the right end
of the PLC. The CJ-series PLC will not operate properly if the End Cover is not
attached.
• 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 in places where the power supply is unstable. An
incorrect power supply 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.
• 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 dissipation.
Leaving the label attached may result in malfunction.
• Do not apply voltages to the Input Units in excess of the rated input voltage. Excess
voltages may result in burning.
• Do not apply voltages or connect loads to the Output Units in excess of the
maximum switching capacity. Excess voltage or loads may result in burning.
• Check the user program for proper execution before actually running it on the Unit.
Not checking the program may result in an unexpected operation.
• Be sure that the terminal blocks, Memory Units, expansion cables, and other items
with locking devices are properly locked into place. Improper locking may result in
malfunction.
• Double-check all wiring and switch settings before turning ON the power supply.
Incorrect wiring may result in burning.
• Disconnect the LR and GR terminals when performing insulation resistance or
withstand voltage tests. Not disconnecting the functional ground terminal may result
in burning.
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 (including the operating mode at power
up).
• Force-setting/force-resetting any bit in memory.
• Changing the present value of any word or any set value in memory.
Do not pull on the cables or bend the cables beyond their natural limit. Doing either of
these may break the cables.
Do not place objects on top of the cables or other wiring lines. Doing so may break the
cables.
Resume operation only after transferring the system parameter data to the CJ1W-
MCH72 and saving the data to flash memory. Not doing so may result in an unexpected
operation.
Confirm that set parameters and data operate properly.
Check the pin numbers before wiring the connectors.
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