YASKAWA 67P-RTP0, Manual

Page: 62 / 73

Electromagnetic interferences may interfere your control via different ways:
n Electromagnetic fields (RF coupling)
n Magnetic fields with power frequency
n Bus system
n Power supply
n Protected earth conductor
Depending on the spreading medium (lead bound or lead free) and the distance to the
interference cause, interferences to your control occur by means of different coupling
mechanisms.
There are:
n galvanic coupling
n capacitive coupling
n inductive coupling
n radiant coupling
The following table shows the four different coupling mechanisms, their causes and pos-
sible interference sources.
Coupling mechanism Cause Typical source
Galvanic coupling Galvanic or metallic coupling always
occurs, when two current circuits have
a common line.
n
Pulsed devices (Net influence from
transducers and foreign net
devices)
n Starting motors
n
Different potential of component
cubicles with common current
supply
n Static discharges
Capacitate coupling Capacitate or electric coupling occurs
between conductors with different
potential. The coupling is propor-
tionate to the temporal change of the
voltage.
n Interference through parallel signal
lines
n Static discharge of the personnel
n Contactors
Possible interference
causes
Coupling mechanisms and
interference sources
HMI
Industrial security and installation guidelines
Installation guidelines > Basic rules for the EMC-equitable assembly of installations
HB160 | PPC | 67P-RTP0 | en | 22-22 62