Application Precautions - Omron CJ - 10-2005 Manual

Application Precautions

5 Application Precautions
!WARNING
!Caution Failure to abide by the following precautions could lead to faulty operation of
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Observe the following precautions when using the PLC System.
Always heed these precautions. Failure to abide by the following precautions
could lead to serious or possibly fatal injury.
• Always connect to a class-3 ground (to 100 Ω or less) when installing the
Units. Not connecting to a class-3 ground may result in electric shock.
• Always turn OFF the power supply to the PLC before attempting any of
the following. Not turning OFF the power supply may result in malfunction
or electric shock.
• Mounting or dismounting I/O Units, CPU Unit, Power Supply Units, In-
ner Boards, or any other Units.
• Assembling the Units.
• Setting DIP switches or rotary switches.
• Connecting or wiring the cables.
• Connecting or disconnecting the connectors.
the PLC or the system, or could damage the PLC or PLC Units. Always heed
these precautions.
• 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 cir-
cuits (i.e., not in the Programmable Controller) must be provided by the
customer.
• Install external breakers and take other safety measures against short-cir-
cuiting in external wiring. Insufficient safety measures against short-cir-
cuiting may result in burning.
• Be sure that all the mounting screws, terminal screws, and cable connec-
tor screws are tightened to the torque specified in the relevant manuals.
Incorrect tightening torque may result in malfunction.
• Always use the power supply voltage 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.
• Do not apply voltages to the Input Units in excess of the rated input volt-
age. 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.
• Wire the Unit correctly.
• Mount the Unit only after checking the terminal block completely.
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