Safety Precautions - Mitsubishi Electric MELSEC iQ-F Series User Manual

SAFETY PRECAUTIONS

(Read the precautions before using this product.)
Before using this product, please read this manual and the relevant manuals carefully and pay full attention to safety to handle
the product correctly.
If the equipment is used in a manner not specified by the manufacturer, the protection provided by the equipment may be
impaired.
This manual classifies the safety precautions into two categories: [
WARNING
CAUTION
Depending on the circumstances, procedures indicated by [
Observe the precautions of both levels because they are important for personal and system safety.
Ensure that the end users read this manual and then keep the manual in a safe place for future reference.
[DESIGN PRECAUTIONS]
WARNING
● Make sure to set up the following safety circuits outside the programmable controller to ensure safe
system operation even during external power supply problems or programmable controller failure.
Otherwise, malfunctions may cause serious accidents.
- Emergency stop circuits, protection circuits, and protective interlock circuits (for conflicting
operations such as forward/reverse rotations or for preventing damage to the equipment such as
upper/lower limit positioning) must be configured external to the programmable controller.
- Note that when the CPU module detects an error, such as a watchdog timer error, during self-
diagnosis, all outputs are turned off. Also, when an error occurs in an input/output control block,
where it cannot be detected by the CPU module, output control may be disabled. External circuits
and mechanisms should be designed to ensure safe machinery operation in such a case.
- Note that the output current of the 24VDC service power supply varies depending on the model
and the absence/presence of extension modules. If an overload occurs, the voltage automatically
drops, inputs in the programmable controller are disabled, and all outputs are turned off. External
circuits and mechanisms should be designed to ensure safe machinery operation in such a case.
- Note that when an error occurs in a relay, triac or transistor of an output circuit, the output might
stay on or off. For output signals that may lead to serious accidents, external circuits and
mechanisms should be designed to ensure safe machinery operation in such a case.
● Construct an interlock circuit in the program so that the whole system always operates on the safe
side before executing the control (for data change) of the programmable controller in operation. Read
the manual thoroughly and ensure complete safety before executing other controls (program change,
parameter change, forced output, and operation status change) to the programmable controller in
operation.
Improper operation may damage machines or cause accidents.
● In an output circuit, when a load current exceeding the current rating or an overcurrent caused by a
load short-circuit flows for a long time, it may cause smoke and fire. To prevent this, configure an
external safety circuit, such as a fuse.
● For the operating status of each station after a communication failure of the network, refer to relevant
manuals for the network. Incorrect output or malfunction may result in an accident.
Indicates that incorrect handling may cause hazardous conditions, resulting in
death or severe injury.
Indicates that incorrect handling may cause hazardous conditions, resulting in
minor or moderate injury or property damage.
WARNING] and [
CAUTION] may also cause severe injury.
CAUTION].
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