Eaton DC1-124D1FN-A20N - Mains Contactors; EMC Compliance

2 Engineering
2.4 EMC compliance
36 DC1 Frequency Inverter 10/12 MN04020003Z-EN www.eaton.com
The size of the leakage currents is mainly dependent upon the:
• length of the motor cable,
• shielding of the motor cable,
• height of the pulse frequency (switching frequency of the inverter),
• Design of the radio interference suppression filter
• grounding measures at the site of the motor.
2.3.3 Mains contactors
The mains contactor enables an operational switching on and off of the sup-
ply voltage for the frequency inverter and switching off in case of a fault.
The mains contactor is designed based on the mains-side input current I
LN
of
the frequency inverter for utilization category AC-1 (IEC 60947) and the ambi-
ent air temperature at the location of use. Mains contactors and their assign-
ment to the frequency inverters belonging to the DC1 series are listed in the
appendix on Page 178.
2.4 EMC compliance
Electrical components in a system (machine) have a reciprocal effect on each
other. Each device not only emits interference but is also affected by it. This
occurs as a result of galvanic, capacitive and/or inductive coupling or through
electromagnetic radiation. In practice, the limit between line-conducted inter-
ference and emitted interference is around 30 MHz. At values above 30 MHz
the lines and cables act like antennas and radiate the electromagnetic waves.
Electromagnetic compatibility (EMC) for frequency controlled drives (variable
speed drives) is implemented in accordance with product standard IEC/EN
61800-3. This includes the complete power magnet system (PDS = Power
Drive System), from the mains supply to the motor, including all compo-
nents, as well as cables  Figure 8, page 29. This type of magnet system
can consist of several individual drives.
The generic standards of the individual components in a magnet system
compliant with IEC/EN 61800-3 do not apply. These component manufactur-
ers, however, must offer solutions that ensure standards-compliant use.
In Europe, maintaining the EMC Directive is mandatory.
￫
While planning the project, make sure that inching operation is
not done via the mains contactor of the frequency inverter on
frequency-controlled drives, but through a controller input of the
frequency inverter.
The maximum permissible mains voltage switch-on frequency
for the
DC1 frequency inverter is once every 30 seconds (normal
operation).