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Operating Environment Precautions
4
• The PLC outputs may remain ON or OFF due to deposition or burning of
the output relays or destruction of the output transistors. As a counter-
measure for such problems, external safety measures must be provided
to ensure safety in the system.
• When the 24-VDC output (service power supply to the PLC) is overloaded
or short-circuited, the voltage may drop and result in the outputs being
turned OFF. As a countermeasure for such problems, external safety
measures must be provided to ensure safety in the system.
!WARNING
Do not attempt to disassemble, repair, or modify any Units. Any attempt to do
so may result in malfunction, fire, or electric shock.
!Caution
Execute online edit only after confirming that no adverse effects will be
caused by extending the cycle time. Otherwise, the input signals may not be
readable.
!Caution
Confirm safety at the destination node before transferring a program to
another node or editing the I/O area. Doing either of these without confirming
safety may result in injury.
!Caution
Tighten the screws on the terminal block of the AC Power Supply Unit to the
torque specified in the operation manual. The loose screws may result in
burning or malfunction.
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Operating Environment Precautions
!Caution
Do not operate the control system in the following places:
• Locations subject to direct sunlight
• Locations subject to temperatures or humidity outside the range specified
in the specifications
• Locations subject to condensation as the result of severe changes in tem-
perature
• Locations subject to corrosive or flammable gases
• Locations subject to dust (especially iron dust) or salts
• Locations subject to exposure to water, oil, or chemicals
• Locations subject to shock or vibration
!Caution
Take appropriate and sufficient countermeasures when installing systems in
the following locations:
• Locations subject to static electricity or other forms of noise
• Locations subject to strong electromagnetic fields
• Locations subject to possible exposure to radioactivity
• Locations close to power supplies
