Mitsubishi Electric MELSEC A Series User Manual page 6

[WIRING PRECAUTIONS]
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.
When turning on the power supply or operating the module after
installation or wiring work, be sure that the module's terminal covers are
correctly attached. Not attaching the terminal cover could result in
electric shock.
Be sure to ground the FG terminals and LG terminals to the protective
ground conductor. Not doing so could result in electric shock or
erroneous operation.
When wiring in the PLC, be sure that it is done correctly by checking the
product's rated voltage and the terminal layout. Connecting a power
supply that is different from the rating or incorrectly wiring the product
could result in fire or damage.
Do not connect multiple power supply modules in parallel. Doing so
could cause overheating, fire or damage to the power supply module.
External connections shall be crimped or pressure welded with the
specified tools, or correctly soldered. Imperfect connections could result
in short circuit, fires, or erroneous operation.
Tighten the terminal screws with the specified torque. If the terminal
screws are loose, it could result in short circuits, fire, or erroneous
operation. Tightening the terminal screws too far may cause damages to
the screws and/or the module, resulting in fallout, short circuits, or
malfunction.
Be sure there are no foreign substances such as sawdust or wiring
debris inside the module. Such debris could cause fires, damage, or
erroneous operation.
The module has an ingress prevention label on its top to prevent foreign
matter, such as wire offcuts, from entering the module during wiring.
Do not peel this label during wiring.
Before starting system operation, be sure to peel this label because of
heat dissipation.
DANGER
CAUTION
A-5