Mitsubishi Electric Q26UD(E)HCPU User Manual page 6

[Wiring Precautions]
● Individually ground the FG and LG terminals of the programmable controller with a ground resistance
of 100  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 the terminal 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 connection must be crimped or pressed with the tool specified by the
manufacturer, or must be correctly soldered. Incomplete connections could result in short circuit, fire,
or malfunction.
● Install the connector to the module securely. Poor contact may cause 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 wires or 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 connection.
● Connect the cable correctly after confirming the interface type to be connected. Connecting to the
wrong interface or incorrect wiring can result in a failure of the module or external devices.
● Tighten the terminal screw 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.
● 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.
● Do not pull the cable section of a cable for disconnection. When disconnecting a cable with a
connector, hold the connector and pull it. When disconnecting a cable on a terminal block, loosen the
terminal screw before disconnection. Pulling the connected cable can result in malfunction or damage
of the module or the cable.
● 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 maintenance personnel who is
familiar with protection against electric shock. (For wiring methods, refer to Page 103, Section 4.8.1.)
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CAUTION