Handling; Cable Length Restrictions Between Stations - Mitsubishi MELSEC-QnA Series User Manual

3. Handling

[INSTALLATION PRECAUTIONS]
Use the PLC in an environment that meets the general specificaitons
contained in CPU module user's manual. Using this PLC in an environment
outside the range of the general specifications could result in electric shock,
fire, erroneous operation, and damage to or deterioration of the product.
Fully insert the projection on the bottom of the module into the hole in the
base unit, press the module into position, and tighten the module fixing
screws.
Not installing the module correctly or not fixing it with the screws could result
in malfunction, damage, or drop of some pieces of the product.
Always tighten the module fixing screws within the specified torque range.
Loose tightening could result in drop of some pieces of the product,
short-circuit, and malfunction.
Tightening the screws too much could result in drop of some pieces of the
product, short-circuit, or malfunction due to the breakage of a screw or the
module.
Completely turn off the externally supplied power used in the system before
mounting or removing the module.
Not doing so could result in damage to the product.
Do not directly touch the printed circuit board, the conducting parts and
electronic parts of the module. It may cause damage or erroneous operation.
Before handling the module, touch a grounded metal object to discharge the
static electricity from the human body. Failure to do so may cause
malfunction or failure of the module.

3.1 Cable length restrictions between stations

(1) The main modules case is made of plastic, so do not drop it or subject it to
strong impacts.
(2) Do not dismount the printed wiring board from the case. It may damage the
module.
(3) When wiring, be careful never to let foreign matter from the above module
such as wiring scraps get inside the module. If something goes in, get rid of
it.
(4) The module installation screw should be kept within the following range.
Screw Locations
Module installation screws (M4 screws)
CAUTION
Tightening Torque Range
4
78 to 118N cm