Specifications

WARNING
The earth leakage current from the frequency converter
exceeds 3.5 mA. To ensure a good mechanical
connection from the earth cable to the earth connection
(terminal 95), the cable cross-section must be at least 10
mm
2
or 2 rated earth wires terminated separately.
5.7 EMC-correct Installation
5.7.1 Electrical Installation - EMC
Precautions
Follow the EMC-correct guidelines below to comply with
EN 61800-3 First environment. If the installation is in EN
61800-3 Second environment, deviation from these
guidelines is allowed but not recommended. See also
paragraphs 2.2 CE Labelling, 2.9 General aspects of EMC and
2.9.3 EMC Test Results (Emission)
Good engineering practice to ensure EMC-correct
electrical installation:
•
Use only braided screened/armoured motor
cables and braided screened/armoured control
cables. The screen should provide a minimum
coverage of 80%. The screen material is metal,
typically copper, aluminium, steel or lead. There
are no special requirements for the mains cable.
•
Installations using rigid metal conduits do not
require screened cable, but the motor cable must
be installed in conduit separate from the control
and mains cables. Full connection of the conduit
from the drive to the motor is required. The EMC
performance of flexible conduits varies. Contact
the manufacturer for more information.
•
Connect the screen/armour/conduit to earth at
both ends for motor cables as well as for control
cables. In some cases, it is not possible to
connect the screen in both ends. In such cases,
connect the screen at the frequency converter.
See also 5.7.1 Electrical Installation - EMC
Precautions
•
Avoid terminating the screen/armour with twisted
ends (pigtails). It increases the high frequency
impedance of the screen, which reduces its
effectiveness at high frequencies. Use low
impedance cable clamps or EMC cable glands
instead.
•
Avoid using unscreened/unarmoured motor or
control cables inside cabinets housing the
frequency converter, whenever possible.
Leave the screen as close to the connectors as possible.
Illustration 5.104 shows an example of an EMC-correct
electrical installation of an IP 20 frequency converter. The
frequency converter is fitted in an installation cabinet with
an output contactor and connected to a PLC, which is
installed in a separate cabinet.
If the installation is not carried out according to the
guideline and if unscreened cables and control wires are
used, some emission requirements are not complied with,
although the immunity requirements are fulfilled.
Transmitter
96 97 9998
91 92 93 95
50
12
L1 L2
L1
PEL3
WPEVU
F1
L2
L3
N
PE
130BA175.12
18
53
37
55
54
M
3
5 kΩ
Illustration 5.103 Electrical Connection Diagram, 6-pulse
Example
How to Install VLT® HVAC Drive FC 102 Design Guide
MG16C102 - Rev. 2013-08-20 151
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