Eaton PowerXL DM1 Series - EMC Installation; EMC Measures in the Control Panel; Earthing; Screen Earth Kit

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Chapter 5—Electrical installation
POWERXL SERIES VFDS MN040060EN—September 2020 www.eaton.com
EMC installation
ote: N All following information is strongly recommended
but is not necessary if sufficient system design and
validation has been completed.
The responsibility to meet the local system EMC limit values
and electromagnetic compatibility requirements is the
responsibility of the end user or the system operator. This
operator must also take measures to minimize or remove
emissions in the environment concerned (see Figure 8). He
must also use means to increase the interference immunity
of the system devices.
In a drive system (PDS) with frequency inverters, you should
take measures for electromagnetic compatibility (EMC) while
doing your planning, because changes or improvements to
the installation site, which are required in the installation
or while mounting, are normally associated with additional
higher costs.
The technology and system of a frequency inverter cause the
flow of high frequency leakage current during operation. All
grounding measures must therefore be implemented with
low impedance connections over a large surface area.
With leakage currents greater than 3.5 mA, in accordance
with VDE 0160 or EN61800-5-1, either:
•
the protective earthing conductor must have a cross-
section of at least 10 mm
2
Cu;
•
the protective earthing conductor must be open-circuit
monitored, and the supply must be automatically
disconnected in case of discontinuity of the protective
earthing conductor, or;
•
the second protective earthing conductor must be fitted.
For an EMC-compliant installation, we recommend the
following measures:
•
Installation of the frequency inverter in a metallic,
electrically conducting enclosure with a good connection
to earth;
•
Shielded motor cables (short cable lengths);
•
Ground all conductive components and housings in a drive
system using as short a line as possible with the greatest
possible cross-section (Cu-braid).
EMC measures in the control panel
For EMC-compatible installation, connect all metallic parts
of the device and the switching cabinet together over broad
surfaces and so that high-frequencies will be conducted.
Mounting plates and cabinet doors should make good
contact and be connected with short HF-braided cables. It
is recommended to avoid using painted surfaces (anodized,
chromized). An overview of all EMC measures is provided in
Figure 8.
Install the frequency inverter as directly as possible (without
spacers) on a metal plate (mounting plate).
Route input and motor cables in the switch cabinet as close
to the ground potential as possible. This is because free
moving cables act as antennas.
When laying HF cables (for example, shielded motor cables) or
suppressed cables (for example, input supply cables, control
circuit and signal cables) in parallel, a minimum clearance of
11.81 in. (300 mm) is recommended in order to prevent the
radiation of electromagnetic energy. Separate cable routing is
also recommended when large voltage potential differences
are involved. Any necessary crossed cabling between the
control signal and power cables should be implemented at
right angles (90 degrees).
It is recommended to never lay control or signal cables
in the same duct as power cables. Analog signal cables
(measured, reference and correction values) should
beshielded.
ote: N The shielded cables need to be grounded according to
section “Screen earth kit” to grounding.
Earthing
The ground connection (PE) in the cabinet should be
connected from the input supply to a central earth point
(mounting plate). All protective conductors should be routed
in star formation from this earth point and all conductive
components of the PDS (frequency inverter, motor reactor,
motor filter, main choke) are to be connected.
Avoid ground loops when installing multiple frequency
inverters in one cabinet. Make sure that all metallic devices
that are to be grounded have a broad area connection with
the mounting plate.
Screen earth kit
Cables that are not shielded work like antennas (sending,
receiving). Make sure that any cables that may carry disruptive
signals (for example, motor cables) and sensitive cables
(analog signal and measurement values) are shielded apart
from one another with EMC-compatible connections.
The effectiveness of the cable shield depends on a good
shield connection and a low shield impedance.
It is recommended to use only shields with tinned or
nickel-plated copper braiding. Braided steel shields
areunsuitable.
Control and signal lines (analog, digital) should be grounded
on one end, in the immediate vicinity of the supply voltage
source (PES).