
8. LOADING AND INSTALLATION
8 - 7
MELSEC-A
8.4
Module Mounting
This section gives the mounting instructions for the main base unit and extension
base units.
8.4.1
Mounting instructions
The instructions for mounting the PLC to a panel, etc. are presented below :
(1)
To improve ventilation and facilitate the replacement of the module, provide
30 mm (1.18 in.) or more of clearance around the PLC.
However, when an extension base unit of one of models A52B, A55B, A58B,
A62B, A65B, and A68B is used, allow a clearance of 80 mm (3.15 in.) or more
between the top face of the module and the surface of a structure or
component.
(2)
Do not mount the base unit vertically or horizontally since this will obstruct
ventilation.
(3)
Ensure that the base unit mounting surface is uniform to prevent strain. If
excessive force is applied to the printed circuit boards, this will result in
incorrect operation. Therefore, mount the base unit on a flat surface.
(4)
Avoid mounting the base unit close to vibration sources, such as large
magnetic contactors and no-fuse breakers, install the base unit in another
panel or distance the base unit from the vibration source.
(5)
Provide a wiring duct as necessary.
However, if the dimensions from the top and bottom of the PLC are less than
those shown in Fig. 8.1, note the following points :
(a)
When the duct is located above the PLC, the height of the duct should
be 50 mm (1.97 in.) or less to allow for sufficient ventilation.
Between the duct and the top of the PLC, provide a sufficient distance to
allow the cable to be removed by opening the cable connector fixing the
lever.
If the lever at the top of the module cannot be opened, it will not be
possible to replace the module.
(b)
If a duct is built under the PLC, provide a clearance between the bottom
surface of the PLC and the surface of the duct so that the input power
cable (100/200 V AC) of the power supply module and the I/O cables
and the cable for 12/24 V DC of I/O modules are not affected or bent.
(6)
If an equipment which generates noise or heat is positioned in front of the
PLC (i.e, mounted on the back side of a panel door), allow a clearance of 100
mm (3.94 in.) or more between the PLC and the equipment.
Also allow a clearance of 50 mm (1.97 in.) or more between the right/left side
of a base unit and this equipment.
(7)
It is recommendable to fix the base module to the control panel directly using
screws, as this method ensures higher resistance to vibration than when
using a DIN rail.
Содержание A1SH
Страница 15: ...MEMO...