Application Precautions - Omron CJ2 User Manual

Application Precautions

Observe the following precautions when using a CJ-series PLC.
Power Supply
• Always use the power supply voltages specified in the user's manuals. An incorrect voltage may
result in malfunction or burning.
• Exceeding the capacity of the Power Supply Unit may prevent the CPU Unit or other Units from
starting.
• Take appropriate measures to ensure that the specified power with the rated voltage and fre-
quency is supplied. Be particularly careful in places where the power supply is unstable. An incor-
rect power supply may result in malfunction.
• 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 Power Supply Units, I/O Units, CPU Units, or any other Units.
• Assembling the Units.
• Setting DIP switches or rotary switches.
• Connecting cables or wiring the system.
• Connecting or disconnecting the connectors.
• When cross-wiring terminals, the total current for all the terminal will flow in the wire. Make sure
that the current capacity of the wire is sufficient.
• Observe the following precautions when using a Power Supply Unit that supports the Replace-
ment Notification Function.
• Replace the Power Supply Unit within six months if the display on the front of the Power Sup-
ply Unit alternates between 0.0 and A02, or if the alarm output automatically turns OFF.
• Keep the alarm output cable separated from power line and high-voltage lines.
• Do not apply a voltage or connect a load exceeding the specifications to the alarm output.
• Whe storing the Power Supply Unit for more than three months, store it at −20 to 30°C and
25% to 70% humidity to preserve the Replacement Notification Function.
• If the Power Supply Unit is not installed properly, heat buildup may cause the replacement noti-
fication signal to appear at the wrong time or may cause interior elements to deteriorate or
become damaged. Use only the standard installation method.
• Do not touch the terminals on the Power Supply Unit immediately after turning OFF the power
supply. Residual voltage may cause electrical shock.
• Observe the following precautions to prevent failure due to difference in electrical potential if the
computer is connected to the PLC.
• Before connecting a laptop computer to the PLC, disconnect the power supply plug of the
computer from the AC outlet. Residual current in the AC adaptor may cause difference in elec-
trical potential to occur between the computer and the PLC. After you connect the computer
and PLC, supply the power again from the AC adaptor.
• If the computer has a FG terminal, make the connections so that it has the same electrical
potential as the FG (GR) terminal on the PLC.
• If the computer is grounded to a separate location, difference in electrical potential may occur
depending on the grounding conditions.
Installation
• Do not install the PLC near sources of strong high-frequency noise.
• 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 malfunction or damage.
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