Emc-Equitable Cabling - YASKAWA VIPA PPC010 ES Manual

VIPA HMI
Guidelines for assem-
bling and grounding of
inactive metal parts

5.3 EMC-equitable cabling

Line routing
Line routing inside and
outside of cubicles
HB160 | PPC | 67K-PNL0 | GB | 16-40
When assembling the devices, you have to ensure the large-surface
grounding of the inactive metal parts. A correctly done grounding sup-
ports an unambiguous reference potential for the control and reduces
the impact of coupled interferences.
Grounding means the conducting connection of all inactive metal
parts. The sum of all interconnected inactive parts is called ground.
Inactive parts are all conductive parts electrically separated from all
active parts by means of a basic isolation and that may only get
voltage in case of an error.
The ground must not adopt dangerous contact voltage even in case
of an error. Thus you have to connect the ground with the protected
earth conductor. To avoid ground loops, local distant ground construc-
tions (cubicles, construction and machine parts) have to be con-
nected with the protected earth conductor system in star-topology.
Please regard at grounding:
n Connect the inactive metal parts as carefully as the active ones.
n Take care of impedance-low metal-metal-connections, e.g. with
large-surface and well conductive contacts.
n If you include coated or anodized metal parts in the grounding,
you have to come through the isolating protection layers. For this
you may use special contact washers or remove the isolation
layer.
n Protect the connection points from corrosion, e.g. with grease.
n Moveable grounding parts (e.g. cubicle doors) have to be con-
nected via flexible ground strips. The ground strips should be
short and have a large surface, because the surface is decisive
for the diversion of high frequency interferences.
Content of this section is the line routing of bus, signal and supply
lines. Object of the line routing is to suppress the "slurring" at parallel
lines.
For an EMC-equitable routing of the lines it is convenient to divide the
cables in different groups and install each group itself:
Group A
n screened bus and data lines
n screened analog lines
unshielded lines for direct voltage £60V
n
unshielded lines for alternating voltage £25V
n
n Coaxial cables for monitors
Group B
unshielded lines for direct voltage >60V and £400V
n
unshielded lines for alternating voltage >25V and £400V
n
Installation guidelines
EMC-equitable cabling
55