Danfoss VLT CDS 302 User Manual

3.3.12 Electrical Installation - EMC
Protection
The following is a guideline to good engineering practice
when installing frequency converters. To comply with EN
61800-3 First environment, follow these guidelines. If the
installation is in EN 61800-3 Second environment, i.e.
industrial networks, or in an installation with its own
transformer, deviation from these guidelines is allowed, but
not recommended.
Good engineering practice to ensure EMC-correct
electrical installation
•
Use only braided screened/armored motor
compressor cables and braided screened/armored
control cables. The screen should provide a
minimum coverage of 80%. The screen material
must be metal, not limited to but typically
copper, aluminum, steel, or lead. There are no
special requirements for the mains cable.
•
Installations using rigid metal conduits are not
required to use screened cable, but the motor
compressor cable must be installed in conduit
separate from the control and mains cables. Full
connection of the conduit from the frequency
converter to the motor compressor is required.
The EMC performance of exible conduits varies a
lot and information from the manufacturer must
be obtained.
•
Connect the screen/armor/conduit to ground at
both ends for motor compressor cables as well as
for control cables. In some cases, it is not possible
to connect the screen in both ends. If so, connect
the screen at the frequency converter. See also
chapter 3.3.11 Electrical Installation, Control Cables.
•
Avoid terminating the screen/armor with twisted
ends (pigtails). It increases the high frequency
impedance of the screen, which reduces its
eectiveness at high frequencies. Use low
impedance cable clamps or EMC cable glands
instead.
•
Avoid using unscreened/unarmored motor
compressor or control cables inside cabinets
housing the frequency converter(s).
Leave the screen as close to the connectors as possible.
Figure 3.27 shows an example of an EMC-correct electrical
installation of an IP20 frequency converter.
The frequency converter is tted in an installation cabinet
with an output contactor and connected to a PLC, which is
installed in a separate cabinet. Other ways of doing the
installation may have just as good an EMC performance,
provided the above guide lines to engineering practice are
followed. Installing without following the guideline, and
using unscreened cables and control wires do not comply
with all emission requirements, although the immunity
requirements are
fullled.
How to Install
VLT
®
Compressor Drives CDS 302/CDS 303
26 Danfoss A/S © Rev. 2013-07-03 All rights reserved. MG34M422
33

Danfoss VLT CDS 302 Specifications

General

Brand	Danfoss
Model	VLT CDS 302
Category	DC Drives
Language	English