Chapter 12 Compliance with EMC Specifications
The PLC is a kind of open device(installed on another device) and it should be installed in a panel. It is because the
installation may prevent a person from suffering from an accident due to electric shock as the person contacts with
the product(ML200 PLC) and the panel can attenuates the noise generating from the PLC.
In case of ML200 PLC, to restrict EMI emitted from a product, it should be installed in a metallic panel. The
specifications of the metallic panel are as follows.
The panel for PLC should be installed and manufactured as follows.
(1) The panel should be made of SPCC(Cold Rolled Mild Steel)
(2) The plate should be 1.6mm and thicker
(3) The power supplied to the panel should be protected against surge by using insulated transformer.
(4) The panel should be structured so that electric wave is not leaked outside. For instance, make the door
as a box as presented below. The main frame should be also designed to be covered the door in
order to restrict any radiating noise generated from the PLC.
(5) The inside plate of panel should have proper conductivity with a wide surface as possible by eliminating
the plating of the bolt used to be mounted on the main frame in order to secure the electric contact
with the frame.
Pnet I/F Module 2MLL-PSRA, 2MLL-PMEA, 2MLL-PMEB User's Guide
Panel Main frame