15 EMC DIRECTIVES
15.1.2 Installation instructions for EMC Directive
(1) Installation
Motion controller is an open type device and must be installed inside a control
panel for use.
This not only ensures safety but also ensures effective shielding of Motion
controller-generated electromagnetic noise.
(a) Control panel
1) Use a conductive control panel.
2) When attaching the control panel's top plate or base plate, expose bare
metal surface and weld so that good surface contact can be made
between the panel and plate.
3) To ensure good electrical contact with the control panel, mask the paint
on the installation bolts of the inner plate in the control panel so that
contact between surfaces can be ensured over the widest possible area.
4) Ground the control panel with a thick wire so that a low impedance
connection to ground can be ensured even at high frequencies.
5) Holes made in the control panel must be 10cm (3.94inch) diameter or
less. If the holes are 10cm (3.94 inch) or larger, radio frequency noise
may be emitted.
In addition, because radio waves leak through a clearance between the
control panel door and the main unit, reduce the clearance as much as
practicable.
The leakage of radio waves can be suppressed by the direct application
of an EMI gasket on the paint surface.
(2) Connection of power line and ground wire
It is necessary to use the Motion controller grounding terminal only when it is in
the grounded condition. Be sure to ground the grounding for the safety reasons
and EMC Directives.
Ground wire and power supply cable for the Motion controller system must be
connected as described below.
(a) Provide an grounding point near the FG terminals. Ground the FG terminals
(FG : Frame Ground) with the thickest and shortest wire possible. (The wire
length must be 30cm (11.81inch) or shorter.) The FG terminals function is to
pass the noise generated in the Motion controller system to the ground, so
wire the ground wire as short as possible to ensure a low impedance.
The wire itself carries a large noise content and thus short wiring means
that the wire is prevented from acting (noise emission) as an antenna.
15 - 3