Emc-Compliant Electrical Installation - Danfoss VLT CDS 803 Operating Manual

VLT® Compressor Drive CDS 803
Operating Guide
2.
Configure all required settings such as address, baud rate, and so on in parameter group 8-** Communications and Options.
For more details on parameters, refer to VLT® Compressor Drive CDS 803 Programming Guide listed in
sources.
Example
GND
68
69
Illustration 7: RS485 Wiring Connection

3.2.5 EMC-compliant Electrical Installation

To obtain an EMC-compliant installation, be sure to follow all electrical installation instructions. Also, remember to practice the fol-
lowing:
• When using relays, control cables, a signal interface, fieldbus, or brake, connect the shield to the enclosure at both ends. If the
ground path has high impedance, is noisy, or is carrying current, break the shield connection on 1 end to avoid ground current
loops.
• Convey the currents back to the unit using a metal mounting plate. Ensure good electrical contact from the mounting plate by
securely fastening the mounting screws to the drive chassis.
• Use shielded cables for motor output cables. An alternative is unshielded motor cables within metal conduit.
• Ensure that motor and brake cables are as short as possible to reduce the interference level from the entire system.
• Avoid placing cables with a sensitive signal level alongside motor and brake cables.
• For communication and command/control lines, follow the particular communication protocol standards. For example, USB
must use shielded cables, but RS485/ethernet can use shielded UTP or unshielded UTP cables.
• Ensure that all control terminal connections are rated protective extra low voltage (PELV).
TWISTED SHIELD ENDS (PIGTAILS)
Twisted shield ends increase shield impedance at higher frequencies, which increases the leakage current.
-
Use integrated shield clamps instead of twisted shield ends.
SHIELDED CABLES
If shielded cables or metal conduits are not used, the unit and the installation do not meet regulatory limits on radio frequency
(RF) emission levels.
EMC INTERFERENCE
Failure to isolate power, motor, and control cables can result in unintended behavior or reduced performance.
-
Use shielded cables for motor and control wiring.
-
Provide a minimum 200 mm (7.9 in) separation between mains input, motor cables, and control cables.
20 | Danfoss A/S © 2021.06
+
RS485
N O T I C E
N O T I C E
N O T I C E
Installation
1.2 Additional Re-
AQ321748767627en-000301 / 130R0570