Power Supply; Control Panel - Mitsubishi MELSEC User Manual

9
EMC AND LOW VOLTAGE DIRECTIVES

9.2.3 Power supply

The insulation specification of the power supply module was designed assuming
installation category II. Be sure to use the installation category II power supply to the PLC.
The installation category indicates the durability level against surge voltage generated by
a thunderbolt. Category I has the lowest durability; category IV has the highest durability.
Category II indicates a power supply whose voltage has been reduced by two or more
levels of isolating transformers from the public power distribution.

9.2.4 Control panel

Because the PLC is an open device (a device designed to be stored within another
module), be sure to use it after storing in the control panel.*
(1) Electrical shock prevention
9
- 10 9.2 Requirement to Conform to the Low Voltage Directive
9.2.3 Power supply
Category IV
Figure 9.10 Installation category for power supply module
* : Also, each network remote station needs to be installed inside the control panel.
The control panel must be handled as shown below to protect a person who does not
have adequate knowledge of electricity from an electric shock.
• Lock the control panel so that only those who are trained and have acquired
enough knowledge of electric facilities can open the control panel.
• The control panel must have a structure which automatically stops the power
supply when the box is opened.
• For electric shock protection, use IP20 or greater control panel.
Category III Category II Category I