Mitsubishi Electric MELIPC MI5A1P User Manual page 178

Installation in a control panel
This product 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.
Placing the product inside a conductive control panel ensures safety as well as effective shielding of electromagnetic noise
emitted from the product.
■Control panel
• Use a conductive control panel.
• Mask off the area used for grounding when securing the top or bottom plate to the control panel using bolts.
• 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 10 cm or less. If the diameter is larger than 10 cm, 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.
Manufacturer
KITAGAWA INDUSTRIES CO.,LTD.
Zippertubing (Japan),Ltd.
SEIWA ELECTRIC MFG. CO.,LTD.
The tests were conducted by Mitsubishi Electric Corporation using a control panel having damping characteristics of 37 dB
(maximum) and 30 dB (average) (measured at 3 m distance, 30 to 300 MHz).
■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 30 cm or
shorter).
The role of the LG and FG terminals is to send to ground noise generated by the product, therefore it is necessary to use a
ground wire with as low an impedance as possible. Additionally, the ground cable removes noise, but can carry noise itself,
therefore using a short wire prevents this from acting as an antenna.
• Twist the ground cable extended from the ground point together with the power cable. Twisting this together with the power
cable sends the largest amount of noise generated form the power cable 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 there is not any electrical interengagement between the DIN rail and the
product, ensure conductivity to the extent possible. Methods to obtain conductivity are shown below.
• Screw this product to the control panel. (Do not use the DIN rail)
• Use iron DIN rails, such as TH35-7.5Fe and TH35-15Fe.
APPX
176
Appendix 13 EMC and Low Voltage Directives
Inquiries
www.kitagawa-ind.com
www.ztj.co.jp
www.seiwa.co.jp