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
Inductive coupling
Inductive or magnetic coupling occurs
between two current active line loops.
The magnetic flows associated with
the currents induct interference vol-
tages. The coupling is proportional to
the time related change of the current.
n
Transducers, motors, electric
welding devices
n
Parallel net cables
n
Cables with toggled currents
n
Signal cable with high frequency
n
Unused coils
Radiate power coupling
One talks of radiate power coupling,
when an electromagnetic wave meets
a line circuit. The hit of the wave
inducts currents and voltages.
n
Sender in the neighbourhood (e.g.
walkie-talkie)
n
Sparking lines (sparking plugs,
collector of electric motors,
welding devices)
VIPA HMI
Installation Guidelines
Basic rules for the EMC-equitable assembly of installations
HB160 | TP-ECO | 62E-MHC0 | en | 17-01
70