DIN rail must be conductive; make sure to ground it prior to use. Failure to do so may cause
electric shocks or malfunctions. Undertightening can cause a drop, short circuit or malfunction.
Overtightening can cause a drop, short circuit or malfunction due to damage to the screw or
module.
[WIRING PRECAUTIONS]
!
DANGER
Completely turn off the external power supply when installing or placing wiring. Not completely
turning off all power could result in electric shock or damage to the product.
!
CAUTION
Make sure to ground the control panel where the MELSEC-ST system is installed in the manner
specified for the MELSEC-ST system. Failure to do so may cause electric shocks or
malfunctions.

Check the rated voltage and the terminal layout and wire the system correctly. Connecting an
inappropriate power supply or incorrect wiring could result in fire or damage.