xix
Application Precautions
5
• Pay careful attention to the polarity (+/
−
) when connecting the terminal
blocks or connectors. Wrong connections may cause malfunction of the
system.
• Wire all terminals, communications paths, power supplies lines, and I/O
lines with the specified polarity and voltages. Improper wiring may result
in faulty operation.
• 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.
• Do not mount the Unit near equipment that generates strong high-fre-
quency noise.
• Leave the label attached to the Unit when wiring to prevent wire clippings
and other foreign matter from entering the Unit. Removing the label may
result in malfunction.
• 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.
• Wire correctly and double-check all the wiring or the setting switches
before turning ON the power supply. Incorrect wiring may result in burn-
ing.
• Be sure that the terminal blocks, connectors, expansion cables, and other
items with locking devices are properly locked into place. Improper locking
may result in malfunction.
• Disconnect the LG and GR terminals on the Power Supply Unit before
performing insulation resistance or dielectric strength tests.
• Always use the power supply voltage specified in the operation manual.
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 exceeding the maximum switching capacity to Out-
put Units. The Output Units may be destroyed.
• Check the user program for proper execution before actually running it on
the Unit. Not checking the program may result in an unexpected opera-
tion.
• Always turn OFF the power supplies to the PLC, slaves, and communica-
tions 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,
memory casettes Master Unit, or any other Units
• Mounting or dismounting circuits for Remote I/O Terminals with 3-tier
terminal blocks.
• Assembling the Units
• Setting DIP switches or rotary switches
• Connecting or wiring the cables