Mitsubishi MELSEC Q series User Manual page 7

[Wiring Precautions]
● Individually ground the FG and LG terminals of the programmable controller with a ground resistance
of 100 ohms or less. Failure to do so may result in electric shock or malfunction.
● Use applicable solderless terminals and tighten them within the specified torque range.
If any spade solderless terminal is used, it may be disconnected when a terminal block screw comes
loose, resulting in failure.
● Check the rated voltage and terminal layout before wiring to the module, and connect the cables
correctly. Connecting a power supply with a different voltage rating or incorrect wiring may cause a fire
or failure.
● Connectors for external devices must be crimped or pressed with the tool specified by the
manufacturer, or must be correctly soldered. Incomplete connections may cause short circuit, fire, or
malfunction.
● Securely connect the connector to the module. Poor contact may result in malfunction.
● Do not install the control lines or communication cables together with the main circuit lines or power
cables. Keep a distance of 100mm or more between them. Failure to do so may result in malfunction
due to noise.
● Place the cables in a duct or clamp them. If not, dangling cable may swing or inadvertently be pulled,
resulting in damage to the module or cables or malfunction due to poor contact.
● Check the interface type and correctly connect the cable. Incorrect wiring (connecting the cable to an
incorrect interface) may cause failure of the module and external device.
● Tighten the terminal block screws within the specified torque range. Undertightening can cause short
circuit, fire, or malfunction. Overtightening can damage the screw and/or module, resulting in drop,
short circuit, or malfunction.
● When disconnecting the cable from the module, do not pull the cable by the cable part. For the cable
with connector, hold the connector part of the cable. For the cable connected to the terminal block,
loosen the terminal screw. Pulling the cable connected to the module may result in malfunction or
damage to the module or cable.
● Prevent foreign matter such as dust or wire chips from entering the module. Such foreign matter can
cause a fire, failure, or malfunction.
● A protective film is attached to the top of the module to prevent foreign matter, such as wire chips,
from entering the module during wiring. Do not remove the film during wiring. Remove it for heat
dissipation before system operation.
● To use the high-speed counter function, ground the shield cable on the encoder side (relay box).
Failure to do so may cause malfunction.
● Mitsubishi Electric programmable controllers must be installed in control panels. Connect the main
power supply to the power supply module in the control panel through a relay terminal block.
Wiring and replacement of a power supply module must be performed by qualified maintenance
personnel with knowledge of protection against electric shock.
For wiring methods, refer to the User's Manual (Hardware Design, Maintenance and Inspection) for
the CPU module used.
CAUTION
5