Mitsubishi Electric MELSEC iQ-R Series Configuration Manual page 176

Installation in a control panel
Programmable controller is an open-type device intended to be placed in a conductive control panel or similar type of
enclosure.
Remote modules on each network must be also installed inside the control panel. Waterproof type remote modules can be
installed outside the control panel.
This ensures safety as well as effective shielding of electromagnetic noise emitted from the programmable controller.
■ Control panel
• Use a conductive control panel.
• Mask off an area used for grounding in advance.
• To ensure electrical contact between inner plates and the control panel, mask off the bolt installation areas of each inner
plate so that conductivity can be ensured in the largest area.
• Ground the control panel with a thick ground cable so that low impedance can be ensured even at high frequencies.
• Keep the diameter of the holes on the control panel to 10cm or less. If the diameter is larger than 10cm, electromagnetic
wave may leak. In addition, because electromagnetic wave leaks through a clearance between the control panel and its
door, reduce the clearance as much as possible. Use of EMI gaskets (sealing the clearance) can suppress undesired
radiated emissions.
The tests were conducted by Mitsubishi Electric Corporation using a control panel having damping characteristics of 37dB
(maximum) and 30dB (average) (measured at 3m distance, 30 to 300MHz).
■ Power cable and ground cable
• Provide a ground point to the control panel near the power supply module. Ground the LG and FG terminals of the power
supply module to the ground point with the thickest and shortest ground cable possible (2 or less, a length of 30cm or
shorter).
• Twist the ground cable extended from the ground point with the power cable so that larger amount of noise generated from
the power cable is absorbed to the ground. Note that if a noise filter is attached to the power cable, twisting may not be
required.
■ DIN rails
Aluminum DIN rails may have insulation films. If an electrical contact cannot be secured between a DIN rail and a
programmable controller, take measures to obtain conductivity.
• Screw the programmable controller to the control panel directly, without using a DIN rail.
• Use iron DIN rails, such as TH35-7.5Fe and TH35-15Fe.
■ Extension cables
• Wire cables with extension cables placed in ducts. If not, dangling cable may swing or inadvertently be pulled, resulting in
damage to the module or cables or malfunction due to poor contact.
• Do not clamp the extension cables with the jacket stripped.
• Use the shortest extension cable according to the distance between the base units connected.
APPX
174
Appendix 6 EMC and Low Voltage Directives